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Alessandro CAPRA

Professore Ordinario
Dipartimento di Ingegneria "Enzo Ferrari"

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Pubblicazioni

2023 - Quantifying the Loss of Coral from a Bleaching Event Using Underwater Photogrammetry and AI-Assisted Image Segmentation [Articolo su rivista]
Kopecky, K. L.; Pavoni, G.; Nocerino, E.; Brooks, A. J.; Corsini, M.; Menna, F.; Gallagher, J. P.; Capra, A.; Castagnetti, C.; Rossi, P.; Gruen, A.; Neyer, F.; Muntoni, A.; Ponchio, F.; Cignoni, P.; Troyer, M.; Holbrook, S. J.; Schmitt, R. J.
abstract

Detecting the impacts of natural and anthropogenic disturbances that cause declines in organisms or changes in community composition has long been a focus of ecology. However, a tradeoff often exists between the spatial extent over which relevant data can be collected, and the resolution of those data. Recent advances in underwater photogrammetry, as well as computer vision and machine learning tools that employ artificial intelligence (AI), offer potential solutions with which to resolve this tradeoff. Here, we coupled a rigorous photogrammetric survey method with novel AI-assisted image segmentation software in order to quantify the impact of a coral bleaching event on a tropical reef, both at an ecologically meaningful spatial scale and with high spatial resolution. In addition to outlining our workflow, we highlight three key results: (1) dramatic changes in the three-dimensional surface areas of live and dead coral, as well as the ratio of live to dead colonies before and after bleaching; (2) a size-dependent pattern of mortality in bleached corals, where the largest corals were disproportionately affected, and (3) a significantly greater decline in the surface area of live coral, as revealed by our approximation of the 3D shape compared to the more standard planar area (2D) approach. The technique of photogrammetry allows us to turn 2D images into approximate 3D models in a flexible and efficient way. Increasing the resolution, accuracy, spatial extent, and efficiency with which we can quantify effects of disturbances will improve our ability to understand the ecological consequences that cascade from small to large scales, as well as allow more informed decisions to be made regarding the mitigation of undesired impacts.

2022 - Image-Based Monitoring of Cracks: Effectiveness Analysis of an Open-Source Machine Learning-Assisted Procedure [Articolo su rivista]
Parente, Luigi; Falvo, Eugenia; Castagnetti, Cristina; Grassi, Francesca; Mancini, Francesco; Rossi, Paolo; Capra, Alessandro
abstract

The proper inspection of a cracks pattern over time is a critical diagnosis step to provide a thorough knowledge of the health state of a structure. When monitoring cracks propagating on a planar surface, adopting a single-image-based approach is a more convenient (costly and logistically) solution compared to subjective operators-based solutions. Machine learning (ML)- based monitoring solutions offer the advantage of automation in crack detection; however, complex and time-consuming training must be carried out. This study presents a simple and automated ML-based crack monitoring approach implemented in open sources software that only requires a single image for training. The effectiveness of the approach is assessed conducting work in controlled and real case study sites. For both sites, the generated outputs are significant in terms of accuracy (~1 mm), repeatability (sub-mm) and precision (sub-pixel). The presented results highlight that the successful detection of cracks is achievable with only a straightforward ML-based training procedure conducted on only a single image of the multi-temporal sequence. Furthermore, the use of an innovative camera kit allowed exploiting automated acquisition and transmission fundamental for Internet of Things (IoTs) for structural health monitoring and to reduce user-based operations and increase safety.

2022 - PHOTOGRAMMETRIC AND FLUORESCENCE SOLUTIONS FOR MONITORING OF HABITAT FORMING ORGANISMS [Relazione in Atti di Convegno]
Rossi, P.; Righi, S.; Parente, L.; Castagnetti, C.; Cattini, S.; Di Loro, G.; Falvo, E.; Grassi, F.; Mancini, F.; Rovati, L.; Simonini, R.; Capra, A.
abstract

The development and testing of innovative technologies and automated data analysis methodologies offer tools for the monitoring of complex marine ecosystems and the direct and indirect effects of climate change on natural heritage. Photogrammetric methods allow precise mapping of the underwater landscape as well as detailed three-dimensional (3D) reconstruction of marine structures, improving the study of complex marine ecosystems. Moreover, fluorescence analyses can provide critical information about the health status of marine organisms. Analysing the variations in their self-fluorescence, allow for early detect changes in their physiological state. These applications provide very useful data to evaluate the health state of biodiversity-rich 3D biogenic structures and make measurements of fine-scale changes, with greater precision than existing methodologies. This contribution shows a multidisciplinary approach to the design, development, and implementation of a technological solution based on the above-mentioned optical measuring systems. Such a system is characterized by a reflex camera, LED-based light sources, and filters to allow the analysis of the self-fluorescence signal. The proposed solution aspires to improve the standardization of monitoring plans through non-destructive fine-scale accurate data collection for image analysis and multi-temporal comparisons, providing challenging stepping-stones for habitat-forming anthozoan management and restoration activities. Initial results of tests carried out in controlled conditions are shown. The photogrammetric approach resulted in 3D reconstructions that allow the monitoring of deformations at millimetre scale. The fluorimetry methodology allowed to obtain high-resolution images with great repeatability, which enabled the identification of stressful status even in absence of geometric deformations. The proposed approaches and obtained results are discussed, together with potential issues related to their implementation in a real-world context adopting remotely operative vehicles.

2021 - Needs and gaps in optical underwater technologies and methods for the investigation of marine animal forest 3D-structural complexity [Articolo su rivista]
Rossi, Paolo; Ponti, Massimo; Righi, Sara; Castagnetti, Cristina; Simonini, Roberto; Mancini, Francesco; Agrafiotis, Panagiotis; Bassani, Leonardo; Bruno, Fabio; Cerrano, Carlo; Cignoni, Paolo; Corsini, Massimiliano; Drap, Pierre; Dubbini, Marco; Garrabou, Joaquim; Gori, Andrea; Gracias, Nuno; Ledoux, Jean-Baptiste; Linares, Cristina; Pulido Mantas, Torcuato; Menna, Fabio; Nocerino, Erica; Palma, Marco; Pavoni, Gaia; Ridolfi, Alessandro; Rossi, Sergio; Skarlatos, Dimitrios; Treibitz, Tali; Turicchia, Eva; Yuval, Matan; Capra, Alessandro
abstract

Marine animal forests are benthic communities dominated by sessile suspension feeders (such as sponges, corals, and bivalves) able to generate three-dimensional (3D) frameworks with high structural complexity. The biodiversity and functioning of marine animal forests are strictly related to their 3D complexity. The present paper aims at providing new perspectives in underwater optical surveys. Starting from the current gaps in data collection and analysis that critically limit the study and conservation of marine animal forests, we discuss the main technological and methodological needs for the investigation of their 3D structural complexity at different spatial and temporal scales. Despite recent technological advances, it seems that several issues in data acquisition and processing need to be solved, to properly map the different benthic habitats in which marine animal forests are present, their health status and to measure structural complexity. Proper precision and accuracy should be chosen and assured in relation to the biological and ecological processes investigated. Besides, standardized methods and protocols are strictly necessary to meet the FAIR (findability, accessibility, interoperability, and reusability) data principles for the stewardship of habitat mapping and biodiversity, biomass, and growth data.

2021 - Victoria land, antarctica: An improved geodynamic interpretation based on the strain rate field of the current crustal motion and moho depth model [Articolo su rivista]
Zanutta, A; Negusini, M; Vittuari, L; Martelli, L; Cianfarra, P; Salvini, F; Mancini, F; Sterzai, P; Creati, N; Dubbini, M; Capra, A.
abstract

In Antarctica, the severe climatic conditions and the thick ice sheet that covers the largest and most internal part of the continent make it particularly difficult to systematically carry out geophysical and geodetic observations on a continental scale. It prevents the comprehensive understanding of both the onshore and offshore geology as well as the relationship between the inner part of East Antarctica (EA) and the coastal sector of Victoria Land (VL). With the aim to reduce this gap, in this paper multiple geophysical dataset collected since the 1980s in Antarctica by Programma Nazionale di Ricerche in Antartide (PNRA) were integrated with geodetic observations. In particu-lar, the analyzed data includes: (i) Geodetic time series from Trans Antarctic Mountains DEFormation (TAMDEF), and Victoria Land Network for DEFormation control (VLNDEF) GNSS stations installed in Victoria Land; (ii) the integration of on-shore (ground points data and airborne) gravity measurements in Victoria Land and marine gravity surveys performed in the Ross Sea and the nar-row strip of Southern Ocean facing the coasts of northern Victoria Land. Gravity data modelling has improved the knowledge of the Moho depth of VL and surrounding the offshore areas. By the integration of geodetic and gravitational (or gravity) potential results it was possible to better con-strain/identify four geodynamic blocks characterized by homogeneous geophysical signature: the Southern Ocean to the N, the Ross Sea to the E, the Wilkes Basin to the W, and VL in between. The last block is characterized by a small but significant clockwise rotation relative to East Antarctica. The presence of a N-S to NNW-SSE 1-km step in the Moho in correspondence of the Rennick Geo-dynamic Belt confirms the existence of this crustal scale discontinuity, possibly representing the tectonic boundary between East Antarctica and the northern part of VL block, as previously pro-posed by some geological studies.

2020 - Coral Reef Monitoring by Scuba Divers Using Underwater Photogrammetry and Geodetic Surveying [Articolo su rivista]
Nocerino, Erica; Menna, Fabio; Gruen, Armin; Troyer, Matthias; Capra, Alessandro; Castagnetti, Cristina; Rossi, Paolo; Brooks, Andrew J.; Schmitt, Russell J.; Holbrook, Sally J.
abstract

Underwater photogrammetry is increasingly being used by marine ecologists because of its ability to produce accurate, spatially detailed, non-destructive measurements of benthic communities, coupled with affordability and ease of use. However, independent quality control, rigorous imaging system set-up, optimal geometry design and a strict modeling of the imaging process are essential to achieving a high degree of measurable accuracy and resolution. If a proper photogrammetric approach that enables the formal description of the propagation of measurement error and modeling uncertainties is not undertaken, statements regarding the statistical significance of the results are limited. In this paper, we tackle these critical topics, based on the experience gained in the Moorea Island Digital Ecosystem Avatar (IDEA) project, where we have developed a rigorous underwater photogrammetric pipeline for coral reef monitoring and change detection. Here, we discuss the need for a permanent, underwater geodetic network, which serves to define a temporally stable reference datum and a check for the time series of photogrammetrically derived three-dimensional (3D) models of the reef structure. We present a methodology to evaluate the suitability of several underwater camera systems for photogrammetric and multi-temporal monitoring purposes and stress the importance of camera network geometry to minimize the deformations of photogrammetrically derived 3D reef models. Finally, we incorporate the measurement and modeling uncertainties of the full photogrammetric process into a simple and flexible framework for detecting statistically significant changes among a time series of models.

2020 - Detecting change in coral reef 3D structure using underwater photogrammetry: critical issues and performance metrics [Articolo su rivista]
Rossi, P.; Castagnetti, C.; Capra, A.; Brooks, A. J.; Mancini, F.
abstract

This paper presents a multi-temporal underwater photogrammetric survey of a reef patch located in Moorea, French Polynesia, designed to detect a coral growth of 10–15 mm/year. Structure-from-Motion photogrammetry and underwater imagery allows the three-dimensional quantification of reef structural complexity and ecologically relevant characteristics at the patch scale. A high degree of accuracy and fine resolution are required in order to guarantee the repeatability of surveys over time within the same reference system, meaning a proper geodetic network and acquisition scheme are mandatory. Measuring tools and reference points were properly designed in order to constrain the photogrammetric reconstruction. The network adjustment, performed with distance and height difference observations, provided an average accuracy of ± 1.2 mm and ± 2.9 mm in the horizontal and vertical components, respectively. The final accuracies of photogrammetric reconstructions are on the order of 1 cm and few millimeters for the 2017 and 2018 monitoring campaigns, respectively. This results in realized errors in the comparison of about ± 1 cm. Coordinate variations larger than this magnitude can be reasonably interpreted as coral growth or dissolution. The direct comparison of the two subsequent point clouds is effective in order to evaluate trends in growth and perform morphometric analyses. For highly accurate quantitative assessment of local changes, an expert operator can create and analyze specific 2D profiles that are easily produced from the point clouds.

2020 - Underwater Photogrammetry for Change Detection [Relazione in Atti di Convegno]
Capra, Alessandro; Castagnetti, Cristina; Mancini, Francesco; Rossi, Paolo
abstract

2019 - COMPARISON of DIVER-OPERATED UNDERWATER PHOTOGRAMMETRIC SYSTEMS for CORAL REEF MONITORING [Relazione in Atti di Convegno]
Nocerino, E; Neyer, F; Gruen, A; Troyer, M; Menna, F; Brooks, A; Capra, A; Castagnetti, C; Rossi, Paolo
abstract

Underwater photogrammetry is a well-established technique for measuring and modelling the subaquatic environment in fields ranging from archaeology to marine ecology. While for simple tasks the acquisition and processing of images have become straightforward, applications requiring relative accuracy better then 1:1000 are still considered challenging. This study focuses on the metric evaluation of different off-the-shelf camera systems for making high resolution and high accuracy measurements of coral reefs monitoring through time, where the variations to be measured are in the range of a few centimeters per year. High quality and low-cost systems (reflex and mirrorless vs action cameras, i.e. GoPro) with multiple lenses (prime and zoom), different fields of views (from fisheye to moderate wide angle), pressure housing materials and lens ports (dome and flat) are compared. Tests are repeated at different camera to object distances to investigate distance dependent induced errors and assess the accuracy of the photogrammetrically derived models. An extensive statistical analysis of the different systems is performed and comparisons against reference control point measured through a high precision underwater geodetic network are reported.

2019 - High accuracy underwater photogrammetric surveying [Relazione in Atti di Convegno]
Capra, A.; Castagnetti, C.; Dubbini, M.; Gruen, A.; Guo, T.; Mancini, F.; Neyer, F.; Rossi, P.; Troyer, M.
abstract

The evolution of underwater photogrammetry allows to realize 3D models of submerged object and structures throughout the use of rapid and efficient procedures either in terms of data acquisition and data processing. These procedures are based on solutions that are applied using natural control points, signalized markers and tie points; the most common algorithms are based on Structure from Motion (SfM) approach. The limit of these applications is sometimes due to the final accuracy, especially when the goal is a centimeter level of accuracy. This accuracy should be necessary when dealing with a survey devoted to deformation control purposes. An example is the underwater photogrammetry for the determination of coral growth; it is effectively a movement or a deformation detection issue where the geometric change is almost at centimeter or few centimeters accuracy level. When dealing with deformation control applications, a geodetic network is essential to realize a stable and unambiguous reference frame through the accurate and permanent installation of Ground Control Points (GCPs). Such a network, indeed, permits a robust reference frame for the georeferencing of images blocks in the different époques of data acquisition. Therefore, the comparison among subsequent photogrammetric restitutions is based on homogeneous 3D models that have been oriented in the same absolute reference system. The photogrammetric survey is based on a methodological approach especially adapted to underwater biometry (like coral growth determination) and to underwater archaeology. The approach is suitable both for modeling objects of relatively reduced dimensions and for structures with a length of ten meters or more, such as coral barriers, wrecks and long walls. The paper describes underwater photogrammetric surveys on sites at different extensions, the geodetic GCPs reference network installation and measurements (distance and elevation difference observations) as well as preliminary results of the network adjustment. A brief description of image acquisition at a different scales and the resulting 3D model of first campaign are also shown.

2019 - POTENZIALITÀ E PROBLEMATICHE NELL’UTILIZZO DELLA FOTOGRAMMETRIA SUBACQUEA PER LA MISURA DELL’ACCRESCIMENTO DI COLONIE CORALLIGENE [EVALUATION OF UNDERWATER PHOTOGRAMMETRY’ PERFORMANCES IN THE ASSESSMENT OF CORAL REEF 3D CHANGES] [Articolo su rivista]
Rossi, P.; Castagnetti, C.; Capra, A.; Brooks, A. J.; Mancini, F.
abstract

This paper presents a multi-temporal underwater photogrammetric survey of a reef patch located in Moorea Island (French Polynesia) to detect a coral growth at a required level of accuracy of 10-15 mmyears. An approach based on processing of underwater imagery by the well-known Structure from Motion method and ground control points derived from the adjustment of underwater topographic measurements allowed the three-dimensional quantification of ecological characteristic at patch scale and an assessment of the reef growth and its structural complexity. To guarantee the repeatability of surveys over time at required level of accuracy and spatial resolution, the paper introduces issues related to reference frame, network adjustment and design of photogrammetric surveying. Measuring tools and reference points were properly designed and presented by the authors. The network adjustment performed after measuring distances and height differences, provided an average precision of 1.2 mm and 2.9 mm in the horizontal and vertical component respectively. The final positional precision of photogrammetric reconstructions was in the order of 1 centimeter and few millimeters for 2017 and 2018 monitoring campaigns respectively. Then, the accuracy of the comparison resulted of about 1 cm which represents a factor to be considered in the successive interpretations of coral growth or dissolution phenomena. The direct comparison of the two subsequent point clouds is effective in the evaluation of growth rates and in the successive morphometric analyses. For highly accurate quantitative assessment of local changes, an expert operator can create and analyze specific 2D profiles that easily come from the point clouds.

2018 - New geodetic and gravimetric maps to infer geodynamics of Antarctica with insights on Victoria Land [Articolo su rivista]
Zanutta, Antonio; Negusini, Monia; Vittuari, Luca; Martelli, Leonardo; Cianfarra, Paola; Salvini, Francesco; Mancini, Francesco; Sterzai, Paolo; Dubbini, Marco; Capra, Alessandro
abstract

In order to make inferences on the geodynamics of Antarctica, geodetic and gravimetric maps derived from past and new observations can be used. This paper provides new insights into the geodynamics of Antarctica by integrating data at regional and continental scales. In particular, signatures of geodynamic activity at a regional extent have been investigated in Victoria Land (VL, Antarctica) by means of Global Navigation Satellite System (GNSS) permanent station observations, data from the VLNDEF (Victoria Land Network for Deformation control) discontinuous network, and gravity station measurements. At the continental scale, episodic GNSS observations on VLNDEF sites collected for 20 years, together with continuous data from the International GNSS Service (IGS) and Polar Earth Observing Network (POLENET) sites, were processed, and the Euler pole position assessed with the angular velocity of the Antarctic plate. Both the Bouguer and the free-air gravity anomaly maps were obtained by integrating the available open-access geophysics dataset, and a compilation of 180 gravity measurements collected in the VL within the Italian National Program for Antarctic Research (PNRA) activities. As a result, new evidence has been detected at regional and continental scale. The main absolute motion of VL is towards SE (Ve 9.9 ± 0.26 mm/yr, Vn −11.9 ± 0.27 mm/yr) with a pattern similar to the transforms of the Tasman and Balleny fracture zones produced as consequence of Southern Ocean spreading. Residual velocities of the GNSS stations located in VL confirm the active role of the two main tectonic lineaments of the region, the Rennick–Aviator and the Lillie–Tucker faults with right-lateral sense of shear. The resulting VL gravity anomalies show a NW region characterized by small sized Bouguer anomaly with high uplift rates associated and a SE region with low values of Bouguer anomaly and general subsidence phenomena. The East and West Antarctica are characterized by a different thickness of the Earth’s crust, and the relative velocities obtained by the observed GNSS data confirm that movements between the two regions are negligible. In East Antarctica, the roots of the main subglacial highlands, Gamburtsev Mts and Dronning Maud Land, are present. The Northern Victoria Land (NVL) is characterized by more scattered anomalies. These confirm the differences between the Glacial Isostatic Adjustment (GIA) modeled and observed uplift rates that could be related to deep-seated, regional scale structures.

2018 - 3D Reconstruction of rock paintings: a cost-effective approach based on modern photogrammetry for rapidly mapping archaeological findings [Relazione in Atti di Convegno]
Castagnetti, C; Rossi, P; Capra, A
abstract

The work describes a cost-effective methodology for the creation of 3D virtual models with both metric and photo-realistic content developed for archaeologists who need to rapidly map new findings during their field prospections. The potential of modern photogrammetry approach, based on Structure from Motion (SfM) and dense image matching algorithms, coupled with the use of low-cost cameras is evaluated for the creation of 3D models and orthophotos of rock paintings. The case study is located in Brealito valley, in the Calchaqui basin of the Province of Salta, Argentina. In these wide areas, actually known for the naturalistic value, a huge amount of archeological remains was found and surveyed for the first time in August 2013 within a research project funded by the Italian Ministry of Foreign Affairs. A methodological approach to record the findings in a cost-effective and reliable way is defined, acquisitions are performed with common use instruments such as digital cameras (off-the-shelf and single lens reflex - SLR) and measuring tapes. The novelty of the work lies in defining, experiencing and transferring to operators a simple methodology for digitizing and mapping the archeological heritage in order to provide 2D orthophotos and 3D models. Such methodology allows anyone, archaeologists or unprofessional personnel, to be trained and easily perform a survey in order to document, survey and study the investigated site.

2017 - Combining nadir and oblique UAV imagery to reconstruct quarry topography: methodology and feasibility analysis [Articolo su rivista]
Rossi, Paolo; Mancini, Francesco; Dubbini, Marco; Mazzone, Francesco; Capra, Alessandro
abstract

The feasibility of unmanned-aerial-vehicle-based photogrammetry was assessed for the reconstruction of high-resolution topography and geomorphic features of quarries by nadir and off-nadir imagery. The test site was a quarry located in the rural area of Turi (Bari, southern Italy). Two processing scenarios were created. Nadir images were initially used, and images acquired with off-nadir angles were added. An accurate set of ground control points (GCPs) were surveyed for both georeferencing purposes and validation processes. In the reconstruction of the surfaces, an accuracy of a few centimeters was achieved in the final positioning of point clouds representing the main geometries of quarry environment. However, greatest differences were found along the edges or the lines characterized by sudden slope changes. To better understand such results, some characteristic quarry shapes depicted by both the scenarios were compared to those surveyed by a total station used as an independent benchmark technique. It allowed to define the benefits introduced by the joint use of nadir and oblique images in the delineation of quarry shapes, surface discontinuities and better descriptions of sub-vertical walls. Beside the evaluation of benefits introduced by use of oblique cameras, the effectiveness of the proposed methodology was also discussed with alternative technologies. Unmanned aerial platforms represent an effective solution, with the need for few accurate GCPs.

2017 - Critical issues and key points from the survey to the creation of the historical building information model: The case of Santo Stefano Basilica [Relazione in Atti di Convegno]
Castagnetti, Cristina; Dubbini, Marco; Ricci, Pier Carlo; Rivola, Riccardo; Giannini, Martina; Capra, Alessandro
abstract

The new era of designing in architecture and civil engineering applications lies in the Building Information Modeling (BIM) approach, based on a 3D geometric model including a 3D database. This is easier for new constructions whereas, when dealing with existing buildings, the creation of the BIM is based on the accurate knowledge of the as-built construction. Such a condition is allowed by a 3D survey, often carried out with laser scanning technology or modern photogrammetry, which are able to guarantee an adequate points cloud in terms of resolution and completeness by balancing both time consuming and costs with respect to the request of final accuracy. The BIM approach for existing buildings and even more for historical buildings is not yet a well known and deeply discussed process. There are still several choices to be addressed in the process from the survey to the model and critical issues to be discussed in the modeling step, particularly when dealing with unconventional elements such as deformed geometries or historical elements. The paper describes a comprehensive workflow that goes through the survey and the modeling, allowing to focus on critical issues and key points to obtain a reliable BIM of an existing monument. The case study employed to illustrate the workflow is the Basilica of St. Stefano in Bologna (Italy), a large monumental complex with great religious, historical and architectural assets.

2017 - Geodetic monitoring and geotechnical analyses of subsidence induced settlements of historic structures [Articolo su rivista]
Castagnetti, C; Cosentini, R M; Lancellotta, R; Capra, A
abstract

This paper focuses on the integration of geodetic monitoring and geotechnical modeling for the analyses of subsidence induced settlements in historic structures. The aim is the assessment of the behavior over time of the monuments, with particular attention to differential settlements, in order to evaluate the potential risk scenarios in a preventive strategy. The methodology is applied to the UNESCO site of Modena where the Cathedral and the Ghirlandina Tower are characterized by strong visible deformations due to a complex construction history, the peculiar subsoil conditions and the effects of both natural and man induced subsidence. A 3D finite element numerical model has been developed taking into account the soil characteristics gained by laboratory and in situ tests. The model takes into account the influence of previously existing structures, as well as the subsidence phenomena and provides a settlements profile in agreement with the real dataset collected by high-precision leveling. The geodetic monitoring, carried out since 1984, allows to optimize and then to validate the numerical model giving the Conservation Authority a useful tool to manage the safety of the heritage.

2017 - Integrazione di dati da laser scanner e fotografia digitale per la modellazione tridimensionale di un manufatto architettonico [Relazione in Atti di Convegno]
Tarantino(a), Eufemia; Caradonna(a), Grazia; Abate(b), Giovanni; Curuni(b), Michele; Novelli(a), Antonio; Capra, Alessandro
abstract

2017 - Monitoring geodynamic activity in the Victoria Land, East Antarctica: evidence from GNSS measurements [Articolo su rivista]
Zanutta, A; Negusini, M; Vittuari, L; Cianfarra, P; Salvini, F; Mancini, F; Sterzai, P; Dubbini, M; Galeandro, A; Capra, A.
abstract

GNSS networks in Antarctica are a fundamental tool to define actual crustal displacements due to geological and geophysical processes and to constrain the glacial isostatic models (GIA). A large network devoted to the detection and monitoring of crustal deformations in the Northern Victoria Land (Victoria Land Network for DEFormation control – VLNDEF), was monumented during the 1999–2000 and 2000–2001 field campaigns, as part of Italian National Program for Antarctic Research and surveyed periodically during the Southern summer seasons. In this paper, GPS observations of VLNDEF collected over a more than 15-year span, together with various selected POLENET sites and more than 70 IGS stations, were processed with Bernese Software, using a classical double difference approach. A solution was obtained combining NEQs by means of ADDNEQ2/FODITS tools embedded in Bernese Software. All the Antarctic sites were kept free and a subset of 50 IGS stations were used to frame VLNDEF into ITRF2008. New evidence provided by analysis of GPS time series for the VLNDEF network is presented; also displacements along the vertical component are compared with the recently published GIA models. The absolute velocities indicate an overall displacement of the northern Victoria Land region along the south-east direction (Ve = 10.6 mm/yr, Vn = −11.5 mm/yr) and an average uplift rate of Vu = 0.5 mm/yr. Two GIA models have been analyzed: ICE-6G_C-VM5a proposed by Argus et al. (2014), Peltier et al. (2015) and W12A_v1 by Whitehouse et al. (2012a,b). Up rates, predicted over the VLNDEF sites by the mentioned GIA models, have been extracted and compared with those observed. A preliminary comparison with GPS-derived vertical rates shows that the Victoria Land ICE-6G_C-VM5 and W12A_v1 GIA models predict overestimated uplift rates of 0.7 and 0.9 mm/yr weighted mean residuals respectively. The mean horizontal relative motions within the Victoria Land (VL) area are in most cases negligible, while only a few points exhibit horizontal velocities greater than the confidence level. Such a residual horizontal velocity field could represent some of the tectonic characteristics affecting VL, characterized by block faulting, tilting along NE striking and SE dipping extensional faults. Uplift rates, highlighted in the present paper depict a well defined spatial pattern in the investigated areas. Northward, all sites show a general positive trend up to 2.3 mm/yr. In the central and southern areas small negative trends (up to −1.3 mm/yr) were detected in the vertical displacements. Only the site VL06, located atop the Mt. Melbourne volcano, does not concord with such a general reading, as it is representative of the volcanic complex’s evolution. Observed and predicted uplift rates increase westward (inland) where the ice-load increases. The same behavior is predicted southward by the GIA models; whereas GPS values decrease toward the south pole, due to the movements of a few sites reflecting the neotectonic phenomena acting in the Victoria Land region.

2017 - Primi test cinematici con ricevitori GNSS multi- costellazione e dati GALILEO – analisi delle prestazioni [Relazione in Atti di Convegno]
Cefalo(a), Raffaela; Tarantino(b), Eufemia; Novelli(b), Antonio; Sluga(a), Tatiana; Tommasi(a), Agostino; Capra, Alessandro
abstract

2017 - Relazione. Convegno Geores 2017. GEOMATICS & RESTORATION – Conservation of Cultural Heritage in the Digital Era, Firenze, 22-24 Maggio. Titolo dell’intervento: Critical Issues and key points from the survey to the creation of the historical building information model: the case of Santo Stefano Basilica. (C. Castagnetti, M. Dubbini, R. Rivola; P. C. Ricci, M. Agnoletti, M. Giannini, A Capra). [Altro]
Castagnetti, C.; Dubbini, M.; Rivola, R.; Ricci, P. C.; Agnoletti, M.; Giannini, M.; Capra, A.
abstract

The new era of designing in architecture and civil engineering applications lies in the Building Information Modeling (BIM) approach, based on a 3D geometric model including a 3D database. This is easier for new constructions whereas, when dealing with existing buildings, the creation of the BIM is based on the accurate knowledge of the as-built construction. Such a condition is allowed by a 3D survey, often carried out with laser scanning technology or modern photogrammetry, which are able to guarantee an adequate points cloud in terms of resolution and completeness by balancing both time consuming and costs with respect to the request of final accuracy. The BIM approach for existing buildings and even more for historical buildings is not yet a well known and deeply discussed process. There are still several choices to be addressed in the process from the survey to the model and critical issues to be discussed in the modeling step, particularly when dealing with unconventional elements such as deformed geometries or historical elements.

2017 - Special issue: deformation monitoring [Articolo su rivista]
Wieser, A.; Capra, A.
abstract

2016 - A structural analysis of the Modena Cathedral [Articolo su rivista]
Baraccani, S.; Silvestri, S.; Gaspoarini, G.; Palermo, M.; Trombetti, T.; Silvestri, E.; Lancellotta, R.; Capra, A.
abstract

Historical monuments, by its own features and time evolution, represent a "unicum" characterized by large uncertainties. To reduce the uncertainties and lead to a more robust assessment it is of fundamental importance to carry out a preliminary, but comprehensive, study with the integration of different fields. The scope of this paper is to present a preliminary assessment of the structural “health” of the Modena Cathedral making use of a multi-disciplinary multi-analysis approach. The approach is based on the development of a multi-disciplinary research able to providing an “integrated knowledge” of the building and a kind of multi-analysis method, which seeks to integrate the results of analyses based on different approaches (from simple but more reliable limit schematizations, to more complex but, usually less robust, computer-based models).

2016 - Accuracy assessment of underwater photogrammetric three dimensional modelling for coral reefs [Relazione in Atti di Convegno]
Guo, T.; Capra, A.; Troyer, M.; Gruen, A.; Brooks, A. J.; Hench, J. L.; Schmitt, R. J.; Holbrook, S. J.; Dubbini, M.
abstract

Recent advances in automation of photogrammetric 3D modelling software packages have stimulated interest in reconstructing highly accurate 3D object geometry in unconventional environments such as underwater utilizing simple and low-cost camera systems. The accuracy of underwater 3D modelling is affected by more parameters than in single media cases. This study is part of a larger project on 3D measurements of temporal change of coral cover in tropical waters. It compares the accuracies of 3D point clouds generated by using images acquired from a system camera mounted in an underwater housing and the popular GoPro cameras respectively. A precisely measured calibration frame was placed in the target scene in order to provide accurate control information and also quantify the errors of the modelling procedure. In addition, several objects (cinder blocks) with various shapes were arranged in the air and underwater and 3D point clouds were generated by automated image matching. These were further used to examine the relative accuracy of the point cloud generation by comparing the point clouds of the individual objects with the objects measured by the system camera in air (the best possible values). Given a working distance of about 1.5 m, the GoPro camera can achieve a relative accuracy of 1.3 mm in air and 2.0 mm in water. The system camera achieved an accuracy of 1.8 mm in water, which meets our requirements for coral measurement in this system.

2016 - Diagnostic Use of Laser Scanning Data to Identify Current and Historical Deformations and Geometries: the case of the Modena Cathedral [Relazione in Atti di Convegno]
Castagnetti, Cristina; Silvestri, Elena; Capra, Alessandro
abstract

The paper describes the semi-automatic methodology to analyze the verticality and the horizontality of structural and architectural elements of the Modena cathedral with the aim to use real dataset to validate the new hypothesis about the history of contruction. moreover, the integration with the crack pattern allows to compute the current deformations of the monument.

2016 - INTEGRAZIONE DI TECNICHE GEODETICHE PER LA CONOSCENZA E LA GESTIONE DI COMPLESSI MONUMENTALI: L’HISTORICAL BIM DI SANTO STEFANO A BOLOGNA [Abstract in Atti di Convegno]
Castagnetti, Cristina; Dubbini, Marco; Rivola, Riccardo; Ricci, Pier Carlo; Agnoletti, Michele; Giannini, Martina; Capra, Alessandro
abstract

L’attività di ricerca affronta il tema della documentazione e della conoscenza approfondita dello stato di fatto di complessi storici monumentali finalizzata alla loro tutela e conservazione. Il caso in esame è la Basilica di Santo Stefano a Bologna (BO), conosciuta anche come “Complesso Delle Sette Chiese”, la quale rappresenta un complesso storico di edifici di culto di grande pregio con età che vanno dal V al XI secolo. Agli occhi dei tecnici, il complesso rappresenta un insieme di strutture modificatisi nel tempo e integratesi l’una con l’altra fino a creare l’attuale bellezza e allo stesso tempo l’attuale complessità strutturale. Considerando la prospettiva di coloro che sono deputati alla tutela e conservazione dei beni culturali, Santo Stefano esemplifica, quindi, molto bene la necessità di conoscere in modo accurato e completo la geometria dello stato di fatto con tutte le variazioni architettonico/strutturali che ha subito il complesso nel tempo con il fine di monitorare l’evoluzione del monumento, progettare interventi di consolidamento e restauro nonché programmare e gestire correttamente la manutenzione. L’approccio che fin da subito è stato ritenuto necessario ed efficace per tutti questi scopi è la creazione di un modello geometrico BIM, Building Information Model.

2016 - Les portails et les sculptures de la cathédrale de Modène : problèmes d’histoire de l’art, de documentation, de conservation - II. Le relevé 3D [Relazione in Atti di Convegno]
Rivola, Riccardo; Bertacchini, Eleonora; Castagnetti, Cristina; Capra, Alessandro; Cadignani, Rossella; Piccinini, Francesca; Silvestri, Elena
abstract

The portals of the Cathedral of Modena, as well as the complex of architecture and sculpture of this important monument of Romanesque art in Italy, has long attracted the interest of several scholars in regard to various aspects: historical, structural, stylistic, iconographical. In the nineteenth century there were also partial surveys of the structure and the portals. During the twentieth century, in-depth studies on the architecture and sculpture have produced some campaigns of photogrammetry mapping and more recently laser-scanner measurements. In recent years the entire building and its bell tower (Torre “Ghirlandina”) were involved in a campaign of laserscanning conducted by the University of Modena and Reggio Emilia, which produced high-resolution surveys especially of the sculptures. These measurements were taken for documentation purposes, but also to control the state of conservation and monitoring of the sculptures and architectural structures.

2016 - Monitoring leaning towers by geodetic approaches: Effects of subsidence and earthquake to the Ghirlandina Tower [Articolo su rivista]
Castagnetti, Cristina; Bertacchini, Eleonora; Capra, Alessandro
abstract

The research focuses on structural monitoring and movements identification applied to cultural heritage safeguard. The final purpose is the integration among different and independent technologies for analyzing and investigating the geometry changing over time of ancient leaning towers. The paper deals with a novel strategy implemented by Authors to compute differential vertical displacements starting from results obtained by repeated high precision leveling network adjustments. These results usually aim at monitoring the subsidence phenomenon, while their use in engineering applications is more or less absent in literature. Moreover, the multidisciplinary approach is also able to analyze gradients of lowering in order to extrapolate the trend of the vertical axis and compute structure’s rotations. The approach is applied to the Ghirlandina Tower, Modena (Italy), in order to identify the leaning and the lowering trend. About thirty years of leveling campaigns provide a useful dataset to test the methodology, which is finally validated by the independent observations collected by a pendulum. The approach allows to compute the mean total displacement since 1984 of about 4.7 cm with 30% occurring over the last 6 years. In the same period, the total overhang of the Tower (1.30 m in 2007) increased of about 19.1 mm and 10.4 mm towards south-west. The approach is also able to identify anomalous behavior of the Tower such as the reversal tilting trend due to the scaffolding in the years of restoration and the permanent deformation suffered after the 2012 Emilia Romagna earthquake (failure of 4 mm in 6 months).

2016 - Tecnologie 3D e loro integrazione per la conoscenza e la rappresentazione dei beni culturali: il BIM di Santo Stefano a Bologna. [Abstract in Atti di Convegno]
Castagnetti, Cristina; Rivola, Riccardo; Giannini, Martina; Capra, Alessandro
abstract

L’attività di ricerca affronta il tema della documentazione, della rappresentazione e della conoscenza approfondita dello stato di fatto di complessi storici monumentali finalizzata alla loro tutela e conservazione. Il caso in esame è la Basilica di Santo Stefano a Bologna (BO), insieme di strutture modificatisi nel tempo e integratesi l’una con l’altra fino a creare l’attuale bellezza e allo stesso tempo l’attuale complessità strutturale. La necessità di conoscere in modo accurato e completo la geometria dello stato di fatto con tutte le variazioni architettonico/strutturali subite nel tempo è cruciale per coloro che sono deputati alla tutela e conservazione del bene con il fine di monitorare l’evoluzione del monumento, progettare interventi di consolidamento e restauro nonché programmare e gestire correttamente la manutenzione. L’approccio ritenuto più efficace per tutti questi scopi è la creazione di un modello geometrico BIM, Building Information Model, del bene storico (H-BIM) in cui confluiscono le informazioni di natura geometrica e morfologica ottenute dai rilievi mentre i dati di natura qualitativa sono stati inseriti in un database online su piattaforma web interpellabile. L’aspetto unico e innovativo ricade principalmente nella metodologia che vede l’integrazione di molteplici tecnologie applicata alla straordinaria estensione e frammentarietà dell’intero complesso monumentale. Le attività, svolte nel 2012, hanno visto l’utilizzo di moderne tecniche di rilievo (laser scanning, livellazione di precisione, rilievo topografico e fotogrammetria da drone) e rappresentazione (modellazione BIM e restituzione grafica) nonché la creazione del primo esempio in Italia di H-BIM caratterizzato anche da tutte le anomalie geometriche tipiche di un edificio storico.

2015 - Contribution of Geomatics Engineering and VGI Within the Landslide Risk Assessment Procedures [Relazione in Atti di Convegno]
Mancini, Francesco; Capra, Alessandro; Castagnetti, Cristina; Ceppi, C; Bertacchini, Eleonora; Rivola, Riccardo
abstract

This paper presents a literature review on the methodology called Volunteered Geographic Information (VGI) and its use for Landslide Risk Assessment (LRA). General risk assessment procedures are discussed and the potential contributions of VGI are identified, in particular when quantitative characterization of factors such as Hazard, Vulnerability and Exposure is required. The review shows that the standard LRA procedures may benefit from input given by surveyors when performing hazard assessments, while crowdsourced data would be a valuable support in vulnerability/damage assessment studies. The review also highlights several limitations related to the role of VGI and crowdsourcing in LRA.

2015 - Recent approaches in geodesy and geomatics for structures monitoring [Articolo su rivista]
Capra, Alessandro; Bertacchini, Eleonora; Castagnetti, Cristina; Rivola, Riccardo; Dubbini, Marco
abstract

Monitoring the time history of structures and infrastructures has always been an important area of application of geodetic and geomatic methods. Here we shall concentrate on the item of monitoring ancient buildings because, beyond its intrinsic interest, it provides a good illustration of some of the most recent monitoring techniques. Identifying the overhang, progressive changes of inclination, differential movements of the structure and detailing the study of structural elements are just some examples of the many fundamental and necessary information for structural engineers. Those data are required to study and analyze the behavior of a structure with the purpose to assess the stability . Looking at the several methods offered by Geomatics, laser scanning appears to be the best technology to provide an effective 3D solution to those requirements. Surveying by means of a terrestrial laser scanner, allows to detect a huge number of 3D information with high accuracy in a relatively short time and high accuracy. Just analyzing the point clouds, interesting information along with useful products can be obtained in order to draw some considerations about the investigated structure. This research aims at suggesting a new philosophy for using 3D models in a diagnostic perspective in order to study structures along with their actual dimensions, their stability and so on. Traditionally, indeed, laser scanning is chosen for artistic and architectural studies and the resulting three-dimensional model represents what often is of concern. Furthermore, the use of more classic techniques, such as total station and digital leveling, and LST is fundamental as an integrated approach for the monitoring of ancient buildings. The integration of different techniques allow a redundancy of observation and the possibility to verify the results obtained form independent techniques as is shown throughout some experimental applications.

2015 - Rilievi metrici 3D laser scanning: la torre e le sculture [Capitolo/Saggio]
Bertacchini, Eleonora; Capra, Alessandro; Castagnetti, Cristina; Rivola, Riccardo; Toschi, Isabella
abstract

L’utilizzo delle tecniche di rilievo messe a disposizione dalle discipline geomatiche si dimostra sempre più un prezioso supporto per gli interventi di valorizzazione, restauro e conservazione dell’immenso patrimonio culturale da cui è caratterizzato il nostro Paese. Il contributo descrive le attività di rilievo laser scanning ad altissima risoluzione svolte sull'apparato scultore della Torre Ghirlandina, sito UNESCO di Modena, e le attività di modellazione 3D per la costruzione di un database idoneo alla riproduzione materia delle sculture per scopi conservativi e di valorizzazione.

2015 - Special issue: terrestrial remote sensing for areal deformation monitoring [Articolo su rivista]
Capra, A.; Scaioni, M.; Wieser, A.
abstract

2015 - The Antarctic Regional GPS Network Densification: Status and Results [Relazione in Atti di Convegno]
Matveev, Alexey J.; Milinevsky, Gennadi; Schenke, Hans-Werner; Shibuya, Kazuo; Sjöberg, Lars E.; Zakrajsek, Andrés; Fritsche, Mathias; Rülke, Axel; Dietrich, Reinhard; Groh, Andreas; Knöfel, Christoph; Scheinert, Mirko; Capra, Alessandro; Cisak, Jan; Dongchen, E.; Eiken, Trond; Fox, Adrian; Hothem, Larry D.; Johnston, Gary; Malaimani, E. C.
abstract

We report on the activities related to the IAG Subcommission 1.3f “Regional Reference Frame for Antarctica”. Campaign-style GPS observations have been carried out since 1995. Based on the Bernese GNSS Software the latest analysis yields results for about 30 stations aligned to the terrestrial reference frame solution IGS08. The obtained station motions are discussed in the context of plate kinematics and glacial-isostatic adjustment. It is demonstrated that the activities are a valuable contribution both to the ITRF densification in Antarctica and to geodynamic research.

2015 - 3D reconstruction of an underwater archaelogical site: comparison between low cost cameras [Relazione in Atti di Convegno]
Capra, Alessandro; Dubbini, M; Bertacchini, Eleonora; Castagnetti, Cristina; Mancini, Francesco
abstract

The 3D reconstruction with a metric content of a submerged area, where objects and structures of archaeological interest are found, could play an important role in the research and study activities and even in the digitization of the cultural heritage. The reconstruction of 3D object, of interest for archaeologists, constitutes a starting point in the classification and description of object in digital format and for successive fruition by user after delivering through several media. The starting point is a metric evaluation of the site obtained with photogrammetric surveying and appropriate 3D restitution. The authors have been applying the underwater photogrammetric technique since several years using underwater digital cameras and, in this paper, digital low cost cameras (off-the-shelf). Results of tests made on submerged objects with three cameras are presented: (c) Canon Power Shot G12, (c) Intova Sport HD e (c) GoPro HERO 2. The experimentation had the goal to evaluate the precision in self-calibration procedures, essential for multimedia underwater photogrammetry, and to analyze the quality of 3D restitution. Precisions obtained in the calibration and orientation procedures was assessed by using three cameras, and an homogeneous set control points. Data were processed with (c) Agisoft Photoscan. Successively, 3D models were created and the comparison of the models derived from the use of different cameras was performed. Different potentialities of the used cameras are reported in the discussion section. The 3D restitution of objects and structures was integrated with sea bottom floor morphology in order to achieve a comprehensive description of the site. A possible methodology of survey and representation of submerged objects is therefore illustrated, considering an automatic and a semi-automatic approach.

2014 - GEIS - Geomatics Engineering Innovative Solutions Srl [Spin Off]
Castagnetti, Cristina; Rivola, Riccardo; Bertacchini, Eleonora; Capra, Alessandro; Università di, Modena e. Reggio Emilia
abstract

GEIS è una startup operativa nel campo del rilievo e restituzione tridimensionale con tecnologie integrate. I principali ambiti di attività sono la meccanica di precisione, il facility management, le costruzioni e l'edilizia. Occupandosi di digitalizzaizone 3D di processi e di prodotti, GEIS con i suoi servizi concretizza l'industria 4.0 e accompagna le imprese nel processo di innovazione anche con la formazione.

2014 - Integrating low-frequency and high-frequency geodetic techniques for structural monitoring [Abstract in Atti di Convegno]
Castagnetti, Cristina; Capra, Alessandro; Bertacchini, Eleonora
abstract

2014 - Micro-gravity measurements in northern Victoria-Land, Antarctica:a feasability study [Capitolo/Saggio]
G., Jentzsch; R., Ricker; A., Weise; Capra, Alessandro; M., Dubbini; A., Zanutta
abstract

Within the Italian Antarctic research programme repeated GPS-measurements are being carried out at well installed points in the area of Northern-Victoria-Land (NVL), Antarctica, called VLNDEF: Victoria Land Network for Deformation Control. Although the deformations obtained over a period of 4 years are quite small we consider micro-gravity measurement a suitable complement for geodynamic research. Since the German Federal Institute for Geosciences and Natural Resources (BGR) is active in that area as well, until the year 2010 performing nine expeditions comprising geological and geophysical work, we used the offer to join expedition GANOVEX X during the season 2009/2010. With three gravimeters 13 points of the Italian network near the German station Gondwana were observed. The advantage of such measurements is that they do not require topographic corrections. Thus, the instrumental resolution and the measurement conditions, resp., are the limits for the resolution and accuracy of the measurements. In order to receive a reliable data base we used three well calibrated gravimeters in parallel and repeated the measurements several times. Local effects due to changes of the ice cover and snow fall are below the achieved measurement accuracy, because the points are so exposed that local effects are negligible. Although the elevation differences up to more than 2,700 m are quite strong, the results reveal the feasibility of these measurements in that area: The obtained standard deviations are in the order of ±10 to ±20 μGal.

2014 - On the evaluation of photogrammetric methods for dense 3D surface reconstruction in a metrological context. [Relazione in Atti di Convegno]
Toschi, I.; Capra, A.; De Luca, L.; J., -Angelo Beraldin; Cournoyer,
abstract

This paper discusses a methodology to evaluate the accuracy of recently developed image-based 3D modelling techniques. So far, the emergence of these novel methods has not been supported by the definition of an internationally recognized standard which is fundamental for user confidence and market growth. In order to provide an element of reflection and solution to the different communities involved in 3D imaging, a promising approach is presented in this paper for the assessment of both metric quality and limitations of an open-source suite of tools (Apero/MicMac), developed for the extraction of dense 3D point clouds from a set of un- ordered 2D images. The proposed procedural workflow is performed within a metrological context, through inter-comparisons with ‘reference’ data acquired with two hemispherical laser scanners, one total station, and one laser tracker. The methodology is applied to two case studies, designed in order to analyse the software performances in dealing with both outdoor and environmentally controlled conditions, i.e. the main entrance of Cathédrale de la Major (Marseille, France) and a custom-made scene located at National Research Council of Canada 3D imaging Metrology Laboratory (Ottawa). Comparative data and accuracy evidence produced for both tests allow the study of some key factors affecting 3D model accuracy.

2013 - Attempt of identification of wet areas with ASTER images for archeological studies [Relazione in Atti di Convegno]
Bertacchini, Eleonora; Despini, Francesca; Teggi, Sergio; Capra, Alessandro; M., Dubbini
abstract

Satellite images are a tool increasingly used in environmental monitoring and in recent years have become also strongly used in the field of archaeology. In this study it was conducted an experimental analysis on the identification of wetlands from satellite images in order to identify sites of interest from the archaeological point of view because probable sites of ancient settlements. The studied area is the Plan de la Limagne which is located in North-East of the French city of Clermont-Ferrand. For wet areas identification were used two ASTER satellite images and pre-existing carthography. Different indexes have been used to identify wet areas. First of all, it was used the NDVI (Normalized Difference Vegetation Index) to discriminate bare soils. Secondly, through the Tasseled Cap transform, other indexes were obtained, such as the Greeness Index, the Brightness Index (SBI - Soil Brightnes Index) and the Wetness Index. Then it has been used the ATI index (Apparent Thermal Inertia) that provides information on the thermal inertia of soils. Through these indexes, visual inspection and the study of spectral signatures, it has been tried not only to identify wetlands within the images, but also to find repeatable processes for the detection of these areas. Some "anomalous" areas, that are probably wet areas, have been identified with this procedure. The identification of wet areas has been carried out in a raw way, this is surely a first approximation analysis. Certainly the in situ analysis would provide the possibility of a better evaluation, in fact field measurements could be used to calibrate the model and then find an effective and repeatable procedure for identifying wetlands.

2013 - Integrating airborne and multi-temporal long-range terrestrial laser scanning with total station measurements for mapping and monitoring a compound slow moving rock slide [Articolo su rivista]
Corsini, Alessandro; Castagnetti, Cristina; Bertacchini, Eleonora; Rivola, Riccardo; Ronchetti, Francesco; Capra, Alessandro
abstract

A slow moving compound rock slide located in the northern Apennines of Italy was mapped and monitored through the integration of Airborne Laser Scanning (ALS), multi-temporal long-range Terrestrial Laser Scanning (TLS), and Automated Total Station (ATS) measurements. Landslide features were mapped using a High Resolution Digital Terrain Model (HR-DTM) obtained by merging ALS and TLS data in an Iterative Closest Point (ICP) procedure. Slope movements in the order of centimeters to a few decimeters were quantified with Differential TLS (D-TLS) based on a Surface Matching approach and supported by ATS data to define stable reference surfaces. The integrated approach allowed mapping of the composite geomorphic features of the rock slide under examination, revealing its complex dynamic nature and further proving that laser scanning is a versatile and widely applicable tool for slope process analysis

2013 - Large-scale slope instability affecting SS63 near the Cerreto Pass (northern Apennines, Italy) [Relazione in Atti di Convegno]
Corsini, Alessandro; Ronchetti, Francesco; Bertacchini, Eleonora; Bonacini, Francesco; Calicetti, P; Capra, Alessandro; Castagnetti, Cristina; Piantelli, E; Caputo, G; Truffelli, G.
abstract

National Road SS63 is endangered by large scale slope instability phenomena few km north of the Cerreto Pass (northern Apennines, Italy). At the Col Piagneto slope, SS63 was closed two times in the past 50 years after landslide events. In 1974, the collapse of portion of a rock slide triggered a debris slide that buried more than 50 m of the road track. In 2008, the reactivation of an earth slide in eastern portion of the slope damaged about 400 m of the “new” track built to by-pass the 1974 risk area. In order to evaluate if it is worthwhile keeping the old track open to traffic, or it is maybe better to repair the new track a comprehensive study was financed by Emilia Romagna Region. Research methods included: high resolution DEM, landslides mapping, continuous displacement and groundwater monitoring. Results allowed to assess different semi-quantitative risk scenario for the road structures or vehicles.

2013 - Multi-sensors integrated system for landslide monitoring: critical issues in system setup and data management [Articolo su rivista]
Castagnetti, Cristina; Bertacchini, Eleonora; Corsini, Alessandro; Capra, Alessandro
abstract

This paper discusses critical issues related to the reliability of topographic monitoring systems such as ATS (Automated Total Stations), GNSS (Global Navigation Satellite System) and Ground Based InSAR focusing the attention on controlling the stability of networks infrastructure, which have influence on data correction procedures but are often taken for granted, and on integrating results in GIS (Geographic Information System), under a common reference framework and with respect to open-access ancillary data. The novelty of the paper lies in the demonstration of the efficiency obtained by a proper implementation of the system. Discussion makes reference to an active landslide by using ATS, GNSS and Ground Based InSAR in continuous and periodic mode

2013 - Prefazione [Prefazione o Postfazione]
Capra, A
abstract

2013 - Rapid assessment of landslide activity in Emilia Romagna using GB‐InSAR short surveys [Relazione in Atti di Convegno]
Corsini, Alessandro; Berti, M.; Monni, A.; Pizziolo, M.; Bonacini, Francesco; Cervi, Federico; Ciccarese, G.; Ronchetti, Francesco; Bertacchini, Eleonora; Capra, Alessandro; Gallucci, A.; Generali, M.; Gozza, G.; Pancioli, V.; Pignone, S.; Truffelli, G.
abstract

Rapid assessment of landslide activity is important in case of adverse climatic conditions leading to civil protection’s alerts that require increased surveillance of risk areas. GB-InSAR is nowadays becoming a consolidated near-sensing monitoring technique for slope movements. It can be installed rapidly and it can rapidly provide results in the form of displacement maps. However, it has never been thoroughly tested in radar-hostile conditions such as these posed by large-scale earth slides – earth flows covered by a canopy of trees bushes and meadows, that are the typical landslides in Emilia Romagna Apennine. As sparse small villages, buildings, roads and other lifelines are often built on these landslide bodies, they are of particular concern for civil protection, especially during prolonged rainfall periods that determine attention/alerting conditions. To test the possibility to achieve improved surveillance capability in case of attention needed, a series of GB-InSAR spot campaigns lasting from a week to a month, was carried out in 2010-11 in several landslides of Emilia Romagna Apennine using a commercial interferometric radar. The aim was to evaluate the performance of the technique for rapid assessment of landslide activity, even in case of partly vegetated soil coverage conditions. The paper deals with the results obtained in 3 out of the 11 monitored sites.

2013 - Recent results from the VLNDEF network [Abstract in Atti di Convegno]
Capra, A.; Zanutta, A.; Negusini, M.; Gandolfi, S.; Sarti, P.; Vittuari, L.; Salvini, F.; Cianfarra, P.; and Sterzai, P.
abstract

2013 - Recording systems. GPS satellites for archaeology: surveying around the Puruhuay Lake [Capitolo/Saggio]
Castagnetti, Cristina; Capra, Alessandro
abstract

This chapter deals with the various surveying methods that have been applied to the Puruhuay area. For the study of ancient settlement systems, it is essential to integrate archeological, topographic and geodetic applications, which provide essential geographic information for the archeological interpretation of settlement systems. The contribution of surveyors, engineers and geologists within the team of archaeologists increased the amount of data collected during each field campaign. The chapter describes with details the survey carried out by using GPS technology and the maps production obtained by GIS approach.

2013 - Thirteen years of integrated precipitable water derived by GPS at Mario Zucchelli Station, Antarctica [Articolo su rivista]
P., Sarti; M., Negusini; C., Tomasi; B. H., Petkov; Capra, Alessandro
abstract

Since 1998, the Italian Antarctic Programme is funding space geodetic activities based on the use of episodic and permanent GPS observations. Beside their exploitation in geodynamics, the data can be used to sense the atmosphere and retrieve the water vapour content and variation. The surface pressure and temperature at the GPS tracking sites are necessary to compute the precipitable water; at sites where no information is available, the values can be retrieved from a global grid model. We process the data series of the permanent GPS site TNB1 (Mario Zucchelli Station, Antarctica) from 1998 up to 2010 comparing the use of grid values to the implementation of real surface records. With both approaches, we estimate almost 70000 hourly values of precipitable water over 13 years and we find discrepancies varying between (1.8 ± 0.2) mm in summer and (3.3 ± 0.5) mm in winter. In addition, the discrepancies of the two solutions exhibit a clear seasonal dependency. We validate our results using radio soundings measurements. They agree better with the precipitable water values derived from real surface data. Nevertheless, these latter exhibit dry biases and detect the (77±21) % of the content of moisture measured by the radio soundings. Both GPS and radio sounding observations are processed adopting the most up-to-date strategies to reduce and dominate known systematic errors.

2013 - Validation tests of open-source procedures for digital camera calibration and 3D image-based modelling [Relazione in Atti di Convegno]
Toschi, Isabella; Rivola, Riccardo; Bertacchini, Eleonora; Castagnetti, Cristina; Dubbini, Marco; Capra, Alessandro
abstract

Among the many open-source software solutions recently developed for the extraction of point clouds from a set of un-oriented images, the photogrammetric tools Apero and MicMac (IGN, Institut Géographique National) aim to distinguish themselves by focusing on the accuracy and the metric content of the final result. This paper firstly aims at assessing the accuracy of the simplified and automated calibration procedure offered by the IGN tools. Results obtained with this procedure were compared with those achieved with a test-range calibration approach using a pre-surveyed laboratory test-field. Both direct and a-posteriori validation tests turned out successfully showing the stability and the metric accuracy of the process, even when low textured or reflective surfaces are present in the 3D scene. Afterwards, the possibility of achieving accurate 3D models from the subsequently extracted dense point clouds is also evaluated. Three different types of sculptural elements were chosen as test-objects and "ground-truth" data were acquired with triangulation laser scanners. 3D models derived from point clouds oriented with a simplified relative procedure show a suitable metric accuracy: all comparisons delivered a standard deviation of millimeter-level. The use of Ground Control Points in the orientation phase did not improve significantly the accuracy of the final 3D model, when a small figure-like corbel was used as test-object.

2012 - Critical aspects of an integrated monitoring system for landslides risk management: strategies for a reliable approach [Abstract in Atti di Convegno]
Castagnetti, C.; Bertacchini, E.; Capra, A.; Corsini, A.
abstract

2012 - Estrazione di DTM da una stereocoppia Worldview-1: procedure di orientamento, image-matching e rimozione degli edifici [Articolo su rivista]
Bertacchini, Eleonora; Toschi, Isabella; Rivola, Riccardo; Castagnetti, Cristina; Capra, Alessandro
abstract

L’utilizzo di immagini satellitari ad alta risoluzione acquisite in modalità stereoscopica si sta affermando quale strumento proficuo per la generazione di Modelli Digitali del Terreno (DTM) e della Superficie (DSM). La sfida che si apre oggi è quella di poter rispondere adeguatamente alle esigenze di base di molti settori applicativi, che necessitano di accurati strumenti per la conoscenza della morfologia del territorio e dei suoi mutamenti. Il presente lavoro si è proposto di analizzare e validare le principali fasi in cui si articola la procedura di estrazione di modelli digitali tridimensionali a partire da immagini satellitari, utilizzando quale caso applicativo una stereocoppia pancromatica acquisita along-track dal satellite WorldView-1 nella zona dei colli Albani, a Sud-Est di Roma. L’obiettivo principale è stato quello di individuare un approccio che potesse unire all’accuratezza del dato metrico finale anche il vantaggio di rendere quest’ultimo un adeguato strumento di descrizione della morfologia di ampie porzioni di territorio: in particolare, è stata associata all’estrazione del DSM, quella di un DTM tramite la classificazione ed eliminazione degli oggetti in elevazione sul terreno (ERDAS Imagine 2011). La parte iniziale della sperimentazione è stata volta a confrontare l’accuratezza perseguibile utilizzando il modello parametrico rigoroso e i metodi razionali per la correzione geometrica delle immagini: a tale scopo, sono stati analizzati e confrontati i risultati ottenuti nella fase di orientamento e in quella successiva di estrazione del modello digitale. Il cuore della ricerca sono stati l’applicazione e il confronto di due procedure alternative volte ad ottenere come risultato finale il modello tridimensionale del terreno depurato dalla presenza degli edifici. A tale scopo è stato sperimentato l’algoritmo di classificazione automatica di LPS-eATE, agente contestualmente alla fase di estrazione dell’informazione altimetrica; i risultati ottenuti sono stati confrontati con quelli conseguiti tramite un approccio alternativo, basato sull'estrazione del modello digitale a partire dalle immagini classificate con metodo object-oriented tramite il software eCognition Developer vs. 8.64.1. Entrambe le procedure testate hanno evidenziato potenzialità interessanti e ulteriormente migliorabili, soprattutto in relazione alla fase di interpolazione della nuvola di punti estratta a partire dalle immagini classificate con il secondo approccio.

2012 - Evaluation of flow direction methods against field observations of overland flow dispersion [Articolo su rivista]
Orlandini, Stefano; Moretti, Giovanni; Corticelli, Mauro Alessandro; Santangelo, Paolo Emilio; Capra, Alessandro; Rivola, Riccardo; Albertson, John D.
abstract

The D8, D8-LTD, D∞-LTD, D∞, MD∞, and MD8 flow direction methods are evaluated against field observations of overland flow dispersion obtained from novel experimental methods. Thin flows of cold water were released at selected points on a warmer slope and individual overland flow patterns originating from each of these points were observed using a terrestrial laser scanner and a thermal imaging camera. Land microtopography was determined by using laser returns from the dry land surface, whereas overland flow patterns were determined by using either laser returns or infrared emissions from the wetted portions of the land surface. Planar overland flow dispersion is found to play an important role in the region laying immediately downslope of the point source, but attenuates rapidly as flow propagates downslope. In contrast, existing dispersive flow direction methods are found to provide a continued dispersion with distance downslope. Predicted propagation patterns, for all methods considered here, depend critically on the size h of grid cells involved. All methods are found to be poorly sensitive in extremely fine grids (h ≤ 2 cm), and to be poorly specific in coarse grids (h = 2 m). Satisfactory results are, however, obtained in grids having resolutions h that approach the average flow width (50 cm), with the best performances displayed by the MD8 method in the finest grids (5 ≤ h ≤ 20 cm), and by the MD∞, D∞, and D∞-LTD methods in the coarsest grids (20 cm < h ≤ 1 m).

2012 - Evaluation of flow direction methods against field observations of overland flow dispersion [Relazione in Atti di Convegno]
Orlandini, Stefano; Moretti, Giovanni; Corticelli, Mauro Alessandro; Santangelo, Paolo Emilio; Capra, Alessandro; Rivola, Riccardo; Albertson, John D.
abstract

The D8, D8-LTD, D∞-LTD, D∞, MD∞, and MD8 flow direction methods are evaluated against field observations of overland flow dispersion obtained from novel experimental methods. Thin flows of cold water were released at selected points on a warmer slope and individual overland flow patterns originating from each of these points were observed using a terrestrial laser scanner and a thermal imaging camera. Land microtopography was determined by using laser returns from the dry land surface, whereas overland flow patterns were determined by using either laser returns or infrared emissions from the wetted portions of the land surface. Planar overland flow dispersion is found to play an important role in the region lying immediately downslope of the point source, but attenuates rapidly as flow propagates downslope. In contrast, existing dispersive flow direction methods are found to provide a continued dispersion with distance downslope. Predicted propagation patterns, for all methods considered here, depend critically on the size h of grid cells involved. All methods are found to be poorly sensitive in extremely fine grids (h ≤ 2 cm), and to be poorly specific in coarse grids (h = 2 m). Satisfactory results are, however, obtained in grids having resolutions h that approach the average flow width (50 cm), with the best performances displayed by the MD8 method in the finest grids (5 cm ≤ h ≤ 20 cm), and by the MD∞, D∞, and D∞-LTD methods in the coarsest grids (20 cm < h ≤ 1 m).

2012 - Evaluation of flow direction methods against field observations of overland flow dispersion [Abstract in Rivista]
Orlandini, Stefano; Moretti, Giovanni; Corticelli, Mauro Alessandro; Santangelo, Paolo Emilio; Capra, Alessandro; Rivola, Riccardo; D. Albertson., John
abstract

Despite the broad effort made in grid-based distributed catchment modeling to account for planar overland flow dispersion, actual dispersion experienced by overland flow along a natural slope has not been measured so far, and the ability of terrain analysis methods to reproduce this dispersion has not been evaluated. In the present study, the D8, D8-LTD, D$infty$-LTD, D$infty$, MD$infty$, and MD8 flow direction methods are evaluated against field observations of overland flow dispersion obtained from novel experimental methods. Thin flows of cold (2--10$^circ$C) water were released at selected points on a warmer (15--30$^circ$C) slope and individual overland flow patterns originating from each of these points were observed using a terrestrial laser scanner and a thermal imaging camera. Prior to each experimental water release, a ScanStation C10 terrestrial laser scanner by Leica Geosystems was used to acquire a point cloud having average density of 25~points/cm$^2$. This point cloud was used to generate alternative grid-based digital elevation models having resolution $h$ ranging from 1~cm to 2~m. During the experiments, an Avio Advanced Thermo TVS-500EX camera by Nippon Avionics was used to monitor land surface temperature with resolution better than $0.05^circ$C. The overland flow patterns were also found to be discernible in terrestrial laser scanner reflectance signal acquired immediately following the flow experiments. Overland flow patterns were determined by considering contrasted temperature and reflectance of the dry and wetted land surface portions. Predicted propagation patterns and observed flow patterns were compared by considering the fractions of flow released at the point source that propagates through the grid cells. Predictions of these quantities were directly provided by flow direction methods and by related flow accumulation algorithms. Suitable data for the comparison were derived from observed overland flow patterns by assuming a uniform distribution of flow along each cross section. Planar overland flow dispersion is found to play an important role in the region lying immediately downslope of the point source, but attenuates rapidly as flow propagates downslope displaying a nearly constant width of about 50~cm. In contrast, existing dispersive flow direction methods are found to provide a continued dispersion with distance downslope. Predicted propagation patterns, for all methods considered here, depend critically on $h$. All methods are found to be poorly sensitive in extremely fine grids ($h leq 2$~cm), and to be poorly specific in coarse grids ($h = 2$~m). Satisfactory results are, however, obtained when $h$ approaches the average flow width, with the best performances in terms of Pearson correlation coefficient displayed by the MD8 method in the finest grids ($5~{ m cm} leq h leq 20~{ m cm}$), and by the MD$infty$, D$infty$, and D$infty$-LTD methods in the coarsest grids ($20~{ m cm} < h leq 1~{ m m}$). The results obtained in this study suggest further testing of terrain analysis methods with longer flow patterns and coarser grids. Scale issues affecting the relation between land surface microtopography, dispersion, and size of grid cells involved need then to be addressed to provide a hydrologic model of flow partitioning along the slope directions identified by terrain analysis methods.

2012 - Investigating an active rockslide by long-range laser scanner: alignment strategy and displacements identification [Relazione in Atti di Convegno]
Bertacchini, Eleonora; Capra, Alessandro; Castagnetti, Cristina; Rivola, Riccardo
abstract

Landslides are considered one of the major natural hazards in mountain regions. Nowadays landslides monitoring has become a central issue for Authorities to be able to anticipate hazards. For this reason, several examples exist about landslides monitoring; they may be installed in different configurations depending on purposes and economic resources.The heart of this research is to detect an efficient methodology for the reliable acquisition and interpretation of Terrestrial Laser Scanning (TLS) data: the final purpose is a proposal for a methodology which is based on TLS technology for identifying displacements and extracting geomorphological changes. The approach is clearly based on a multi-temporal analysis which is computed on several repetitions of TLS surveys performed on the area of interest. To achieve best results and optimize the processing strategy, different methods about point clouds alignment have been tested, together with algorithms both for filtering and post- processing. The final aim is also to provide a sort of guidelines about a suitable way for planning and properly carrying out TLS surveys.The case study is the Col Piagneto landslide, located in the North Apennines (Reggio Emilia, Italy) on the right flank of Biola torrent. The large scale composite landslide area is made both by a wide rock slide sector and a more limited earth slide sector. An integrated monitoring system is installed since 2009 and comprises both point-based technologies (extensometers, total station and global positioning system), as well as area-based ones (airborne laser scanner, long-range TLS and ground-based radar). This choice combines the advantages of both approaches.The research focuses on TLS surveys for trying to detect displacements which might be considered responsible for instability. By sequentially analyzing TLS surfaces, displacement maps have been obtained for the rockslide area. Confirmation can be achieved by comparing results with movements of reflectors located on the slope and continuously measured by total station. Such validation strengthens the idea that TLS may be successfully used for analyzing instability.

2012 - La rete VLNDEF per lo studio della geodinamica nella Terra Vittoria settentrionale: risultati recenti di 20 anni di attività geodetica italiana in Antartide [Relazione in Atti di Convegno]
Capra, Alessandro; G., Bitelli; M., Dubbini; A., Galeandro; S., Gandolfi; F., Mancini; M., Negusini; P., Sarti; L., Vittuari; A., Zanutta
abstract

Le misure periodiche e permanenti di osservatorio geodetico, in continuita' con una serie più che ventennale di dati, hanno avuto lo scopo di determinare l’infrastruttura geodetica della Terra Vittoria Settentrionale e di rilevare e monitorare la Terra Vittoria settentrionale. Viene presentata una sintesi delle principali attività condotte recentemente nell’ambito del Progetto di Geodesia del PNRA (Programma Nazionale di Ricerche in Antartide) e vengono presentati i risultati raggiunti nelle ultime campagne di misura pubblicati negli ultimi anni.

2012 - Mappatura GPS delle ippovie e individuazione siti di interesse culturale. Un WebGIS per il turismo equestre [Articolo su rivista]
Castagnetti, Cristina; Capra, Alessandro; Bedostri, Irene; Bedostri, Tiziano
abstract

L'articolo descrive una sperimentazione svolta nell'ambito del progetto "Turismo equestre" in collaborazione con il comitato emilia romagna della Federazione Italiana Sport Equestri volta a mappare attraverso l'utilizzo di strumentazione GPS le ippovie e creare con strumenti GIS dei percorsi da condividere con utenti del settore. L'articolo illustra le potenzialità e i limiti di utilizzo di strumentazione geodetica a questo scopo.

2012 - Tecniche Laser Scanner per la rappresentazione dei beni culturali: il rilievo dell’apparato scultoreo della Torre Ghirlandina di Modena [Relazione in Atti di Convegno]
Bertacchini, Eleonora; Capra, Alessandro; Castagnetti, Cristina; Rivola, Riccardo; Toschi, Isabella
abstract

2012 - Terrestrial Laser Scanning for Preserving Cultural Heritage: Analysis of Geometric Anomalies for Ancient Structures [Relazione in Atti di Convegno]
Castagnetti, Cristina; Bertacchini, Eleonora; Capra, Alessandro; Dubbini, Marco
abstract

Identifying the overhang, progressive changes of inclination, differential movements of the structure and detailing the study of structural elements are just some examples of the many fundamental information for structural engineers. Those data are required to study and analyze the behavior of a structure with the purpose to assess the stability . Laser scanning appears to be the best technology to provide an effective solution to those requirements. Surveying by means of a terrestrial laser scanner (TLS), allows to detect a huge number of information with relatively short time and high accuracy. Those data, then, do not necessarily need to be used to reconstruct the three dimensional surface model. Just analyzing the point clouds, interesting information along with useful products can be obtained in order to draw some considerations about the investigated structure. This research aims to suggest a new philosophy for using TLS in a diagnostic perspective in order to study structures along with their actual dimensions, their stability and so on. This new approach, characterized by a well- advanced vision, is really different from the traditional one because of the engineering point of view with respect to the usual application of TLS. Traditionally, indeed, laser scanning is chosen for artistic and architectural studies and the resulting three-dimensional model represents what often is of concern.The research focuses on the Cathedral of Modena, one of the most important pieces of Romanesque culture in Europe (UNESCO World Heritage List since 1997). The overall motivation of this research is to preserve the cultural heritage we are responsible for, as long as spectators. Thus, the final purpose is to illustrate the methodology to compute anomalies in structural geometry by means of TLS in order to provide an accurate description of the structure that is particularly useful for structural engineers, architects and art historians. Both outdoor as well as indoor TLS surveys were performed. The geometry of the structure was properly described by analyzing point clouds; specific measurements were focused on constituent elements with the aim of detecting anomalies of the geometric configuration. Geometric anomalies might be read as the result of deformations occurred in the past or as future deformations due to an abnormal geometric configuration. Investigations about the identified anomalies will be presented together with differential movements obtained by high precision leveling focused on a network of benchmarks that were installed along the outside perimeter. The integration of independent techniques allows to check for consistency of results.

2011 - Atmospheric corrections for topographic monitoring systems in landslides. [Relazione in Atti di Convegno]
Bertacchini, Eleonora; Capra, Alessandro; Castagnetti, Cristina; Corsini, Alessandro
abstract

SUMMARYNew automated “long range” total stations are actually available for monitoring landslides, dams, structures etc. The use of total station is consolidate within some hundred meters of distance and with a supervisor. But the long range (up to 3 km) measurements are not still completely investigated in operating condition. When the accuracy and the precision required are important, seems to be necessary to investigate the atmosphere influence on distance measurements. The research deals with the study of a landslide topographic monitoring system: the Collagna Landslide (Reggio Emilia, Italy) monitoring system. It consists of an automated long range total station acquiring about 36 prisms ,every 4 hours, since 2009. The idea was to test how atmospheric corrections could improve the measurements precision and accuracy to exploit the system capabilities. Some tests on the total station EDM (Electronic Distance Measuring) system are presented in operating conditions. Particularly attention was paid to the long distances dependence on atmospheric conditions (temperature, pressure and relative humidity). Two kinds of corrections were applied, that of the instrument and one of the literature. Some differences were found on atmospheric corrections calculated with the two different methods. But it seems that atmospheric corrections can really improve the final result accuracy.

2011 - Bollettino SIFET [Direzione o Responsabilità Riviste]
Capra, Alessandro
abstract

2011 - Con una pacarina a la vista: arquitectura como construccion de autoridad alrededor de la laguna de Puruhuay [Capitolo/Saggio]
Orsini, Carolina; Benozzi, Elisa; Debandi, Florencia; Capra, Alessandro; Boni, Emanuele; Castagnetti, Cristina
abstract

Commencing in the eleventh century A.D. a series of settlements and ceremonial sites, in close relationship with the Puruhuay Lake and the waterfall “María Jiray” (Acopalca district, Huari, Ancash) were constructed. The majority of these sites have been studied during the archaeological campaigns of the Project «Antonio Raimondi» between 2006 and 2009. The close relationship between the sites is evident not only because they were built during the same period and within a contiguous territory, but also because of the uniform type of architecture. The complex of settlements built around the lake appear as a planned system of control of a natural place; a natural site that is considered an important pacarina even today, and a resource of great importance for the local economy.

2011 - Design of a Low-cost GPS/magnetometer System for Land-based Navigation: Integration and Autocalibration Algorithms [Relazione in Atti di Convegno]
Castagnetti, Cristina; Biagi, Ludovico; Capra, Alessandro
abstract

The land-based navigation, paying attention to precision farming, is the research topic: the final purpose is the design and development of a guidance-aided system focusing on a low-cost GPS receiver able to provide a pseudorange-based solution only. Specific tests have been carried out to reproduce the trajectories followed by the vehicle in agricultural applications, whose accuracy target is typically 1 m. Results show that the investigated low-cost receiver is affected by a drift in time which is mainly detected while turning and causing a deviation from the optimal reference solution. Thus, the goal is to correct this behavior because the deviation accumulates during time and causes a not optimal treatment of the field (waste of material and money). Paying attention to the cost of the system, a new idea is proposed: the integration between the low-cost GPS with a magnetometer/digital compass. A dedicated algorithm has been also implemented, taking the heading provided by th e magnetometer and using it to correct the deviation in turns. Unluckily a magnetometer is deeply influenced by ferrous materials and the sensor is supposed to be installed on the vehicle, which is mainly made by metal. As a consequence, the sensed measurements are affected by a deviation from the actual magnetic field. Those disturbances need to be properly reduced by an autocalibration procedure. A new approach for the autocalibration problem has been developed and implemented; then the comparison with respect to the traditional method has been also performed in order to test and validate the new idea. A comprehensive and detailed description of all the algorithms will be produced concerning both the sensors integration (GPS and magnetometer) along with the magnetometer autocalibration. Particular attention will be focused on results and performances of the autocalibration procedure, which appears to provide very interesting results. The new approach, which is simply based on the covariance matrix, appears to be more successful than the traditional one. Several tests have been analyzed: the stand-alone low-cost GPS provides solutions which are not acceptable for precision farming applications, while the integration with a magnetometer slightly increases the accuracy. Furthermore, the innovation of the research is connected to the autocalibration algorithm itself. The final goal was the design of a low-cost system for supporting the guidance in land-based navigation; improvements are still required but the goal is close to be achieved.

2011 - GPS potentiality (strategies) for supporting archaeology: preventive investigation and memory of an excavation [Abstract in Atti di Convegno]
Castagnetti, C.; Bertacchini, E.; Capra, A.; Orsini, C.; Dubbini, M.
abstract

2011 - IL LASER SCANNING TERRESTRE PER L'ANALISI DI EDIFICI DI INTERESSE STORICO ED ARTISTICO [Capitolo/Saggio]
Castagnetti, Cristina; Bertacchini, Eleonora; Capra, Alessandro; Dubbini, Marco
abstract

Identifying the overhang, progressive changes of inclination, differential movements of the structure and detailing the study of structural elements are just some examples of the many fundamental and necessary information for structural engineers. Those data are required to study and analyze the behaviour of a structure with the purpose to assess the stability . Looking at the several methods offered by Geomatics, laser scanning appears to be the best technology to provide an effective solution to those requirements. Surveying by means of a terrestrial laser scanner, allows to detect a huge number of information with relatively short time and high accuracy. Those data, then, do not necessarily need to be used to reconstruct the three dimensional surface model. Just analyzing the point clouds, interesting information along with useful products can be obtained in order to draw some considerations about the investigated structure.This research aims to suggest a new philosophy for using the laser scanner in a diagnostic perspective in order to study structures along with their actual dimensions, their stability and so on. This new approach, characterized by a well-advanced vision, is very different from the traditional one because of the engineering point of view with respect to the usual application of laser scanner. Traditionally, indeed, laser scanning is chosen for artistic and architectural studies and the resulting three-dimensional model represents what often is of concern. Some case studies will be presented; they are characterized by different kinds of structures suffering from various problems: the Cathedral of Modena and the Ghirlandina Tower UNESCO-World Heritage (Italy), "della Sagra" Tower in Carpi (Modena – Italy) and Asinelli Tower in Bologna (Italy). The final purpose is to illustrate the methodology to perform the structural analysis by means of terrestrial laser scanning. Furthermore, examples will be presented about extraction of interesting products and results.

2011 - Integrating LIDAR and terrestrial laser scanning for a full and reliable description of landslides geomorphology [Abstract in Atti di Convegno]
Castagnetti, C.; Bertacchini, E.; Capra, A.; Dubbini, M.; Rivola, R.; Corsini, A.
abstract

2011 - L’altezza e l’inclinazione della Torre - Le torri Asinelli e Garisenda: le indagini e gli interventi di consolidamento [Capitolo/Saggio]
Capra, A
abstract

2011 - Registrazione di scansioni laser scanner: potenzialità del metodo diretto. [Articolo su rivista]
Rivola, Riccardo; Bertacchini, Eleonora; Castagnetti, Cristina; Toschi, Isabella; Capra, Alessandro
abstract

Laser scanning technology has emerged on the surveying instrument scene relatively recently, revolutionizing traditional surveying methodologies. In some cases, users rely blindly on this new instrumentation, without bothering to verify its reliability and assess its true potential. For this reason, it was decided to undertake a study to identify the more efficient laser scanning survey techniques and methodologies. The tests were carried out using a pulsed laser scanner and initially focused on traverse precision and accuracy, comparing measurements of that instrument with those of a robotic total station. Subsequent tests analyzed in detail the quality of the direct registration scanning technique compared to the traditional indirect method and the Iterative Closest Point (ICP) procedure. Scan alignment by the direct method takes traverses directly from the Terrestrial Laser Scanner (TLS), thus decoupling acquisition from the traditional topographic instruments used for the support measurements. Comprehensive analysis of these results confirms, for architectural surveys, the more efficient and productive survey methodology has been identified as a function of the object type, the desired result and the time available.

2011 - Rilievi integrati per il monitoraggio e la gestione dell’instabilità dei versanti [Capitolo/Saggio]
Bertacchini, Eleonora; Castagnetti, Cristina; Capra, Alessandro; Rivola, Riccardo; Corsini, Alessandro
abstract

Nowadays civil protection and environment safeguard are of topical interest. The hydro-geological instability and landslides as well, in fact, are serious problems that unfortunately characterize our whole country. The consequences are sometimes severe and there is more to deal with such as emergencies and disasters directly affecting the population. Geomatics, in this sense, offers a wide variety of methodologies and technologies, both well-established and well-advanced, functioning as an important support to the control and monitoring of territory. Key studies concern the phenomenon itself, risk prevention and emergency management . Concerning that, the present paper presents the design and implementation of an integrated system based on topographical and geotechnical instrumentation with the purpose to continuously monitor a landslide. Two case studies will be presented: they are both located in the Apennines of Emilia-Romagna Region. The system consists of a robotic total station located in a geologically stable area together with a GNSS (Global Navigation Satellite System) receiver which acts as a permanent master station. The robotic total station regularly runs several times a day repeating the same action, which consists on measuring a series of prisms positioned both inside and outside of the landslide body. A two-directions inclinometer monitors the stability of the monument in real-time mode. An additional GNSS, acting as a rover receiver, has been placed at the edge of the landslide to assess over time the possible extension of the phenomenon (continuous monitoring). The monitoring system, operating in continuous mode, is remotely managed; this allows a constant control on displacements and ensures a rapid and effective action in case of emergency . Together with the topographic instruments, some extensometers, inclinometers and piezometers were installed with the aim to study the deformation mechanism of the investigated phenomenon. LIDAR (Light Detection And Ranging) surveys were carried out to obtain the DTM (Digital Terrain Model) and high accuracy orthophotos of the area. Periodical flights were performed to detect and study the subsequent reactivations. The present research aims to present some phenomena, which are similar to many others in the country, with the aim of strengthening the role, the importance and the usefulness of Geomatics in the monitoring of the territory.

2011 - Rilievi laser scanner per l’analisi geometrica delle torri degli Asinelli e Garisenda. [Articolo su rivista]
Capra, Alessandro; Bertacchini, Eleonora; Castagnetti, Cristina; Dubbini, Marco; Rivola, Riccardo; Toschi, Isabella
abstract

The Tower of Asinelli and the Garisenda Tower, represent structures with high level of historical content and symbolize the city of Bologna. Erected in the XII century by noble “ghibelline” families, both towers present an evident overhang that led to the choise of a surveying methodology to analyze the geometry of the structures. In this paper the studies conducted on the 3D models of the Towers obtained with laser scanning technology are presented. In both cases, the choices taken during the experimentations, from the execution of the survey to the extraction of information of interest, were conducted to make repeatable analysis and lay the foundation for monitoring the structural behavior.

2011 - Surveillance of landslides risk areas with ground-based interferometric SAR for Civil protection in Emilia Romagna (Italy). [Relazione in Atti di Convegno]
Corsini, Alessandro; F., Cervi; G., Ciccarese; J. P., Iannacone; Ronchetti, Francesco; Bertacchini, Eleonora; Capra, Alessandro; M., Berti; E., Brancaleoni; P., Mora; V., Pancioli; A., Gallucci; G., Gozza; A., Monni; M., Generali; M., Pizziolo; G., Caputo; G., Truffelli; V., Manzi; F., Ghiselli; M., Guida; G., Minardi; C. C., Lucente; A., Bernardi; A., Benini
abstract

Experimental applications of Groune Based SAR to landslides movement/deformation control. The objective was to verify yìthe possibility to apply GBsAR techniques for civil protection activities in Emilia Romagna region relatively to the different types of landslides.

2011 - Utilizzo del laser scanner per i beni culturali: analisi dell’assetto geometrico strutturale e di specifiche anomalie geometriche [Relazione in Atti di Convegno]
Bertacchini, Eleonora; Capra, Alessandro; Castagnetti, Cristina; Dubbini, Marco; Rivola, Riccardo; Toschi, Isabella
abstract

RIASSUNTO:La tecnologia Laser Scanner Terrestre (LST) permette di ottenere il modello tridimensionale complessivo di qualsiasi oggetto con elevata accuratezza e, per questo motivo, risulta oggi sempre più applicata in ambito architettonico. E’ tuttavia necessario identificare l’approccio più adeguato in relazione alla tipologia di oggetto e allo scopo finale del rilievo, intendendo con questo sia la scelta della strumentazione da utilizzare sia l’adozione di specifiche tecniche per il trattamento dei dati.Il presente lavoro si propone di sperimentare l’applicazione della tecnologia LST a strutture di elevato pregio architettonico – culturale: la Torre degli Asinelli e la Torre Garisenda (Bologna). Entrambe richiedono un’attenta analisi strutturale in quanto il loro prevalente sviluppo verticale, denotato da altezza e snellezza significative, le rende una tipologia costruttiva particolarmente delicata. In entrambi i casi il rilievo, eseguito con un laser scanner distanziometrico ad impulsi, ha permesso di ottenere il modello complessivo della struttura con risoluzione sub-centimetrica. Nello specifico, lo studio applicato alla Torre degli Asinelli è stato volto alla determinazione di informazioni generali sull’assetto geometrico della struttura: sono stati infatti ricavati l’altezza della Torre, lo sviluppo del suo asse longitudinale e lo strapiombo. Le analisi relative alla Garisenda hanno invece interessato la fascia selenitica della Torre: all’analisi geometrica delle sezioni orizzontali è stata affiancata quella relativa al fenomeno di “spanciamento” particolarmente evidente su uno dei quattro lati. Le scelte adottate per l’esecuzione del rilievo e l’estrazione delle informazioni hanno permesso un’analisi limitata allo stato di fatto; in futuro verranno messe in campo strategie atte a permettere la ripetibilità nel tempo delle misure e delle successive analisi, al fine di porre le basi per un monitoraggio strutturale. A tale scopo, sarà necessario sperimentare un’adeguata e proficua integrazione tra differenti tecniche e strumentazioni, inquadrando tutte le future sperimentazioni e misure nel medesimo sistema di riferimento assoluto. ABSTRACT: AbstractTerrestrial Laser Scanning Technology (TLS) allows to obtain the overall three-dimensional model of the investigated object with high accuracy. For this reason, such a technology is now increasingly applied in architecture as well. However, strongly fundamental is the choice of the most appropriate approach depending on the type of the object and the final purpose of the survey. Both the choice of the most suitable instrumentation and the use of specific data processing strategies are of concern.This paper aims to test the use of TLS for studying structures with high value from architectural and cultural points of view: Asinelli Tower and Garisenda Tower (located in Bologna-Italy). Both structures require to be carefully analyzed for controlling stability because of their dominant vertical dimension along with their significant slenderness. Those details make them particularly315Atti 15a Conferenza Nazionale ASITA - Reggia di Colorno 15-18 novembre 2011sensitive. The survey was performed with a time-of-flight (pulsed laser) laser scanner and resulted in the overall model of the structure with sub-centimeter resolution. For the Asinelli Tower, the goal was the identification of general information about the geometry of the structure such as the height of the tower, the development of its longitudinal axis and its overhang. Furthermore, for the Garisenda Tower, the analysis was mainly focused on the selenitic area located at the base of the Tower: both the geometry of horizontal sections and the phenomenon of the "belly flops" were investigated. This last one is particularly evident on the East side.All the analyses allowed to extract information about the actual geometry and attitude of the structure at the present. Strategies t

2010 - Active tectonics in Northern Victoria Land (Antarctica) inferred from theintegration of GPS data and geologic setting [Articolo su rivista]
M., Dubbini; P., Cianfarra; G., Casula; Capra, Alessandro; F., Salvini
abstract

A semi-permanent global positioning system (GPS) network of 30 vertices known as theVictoria Land Network for Deformation Control (VLNDEF) was set-up in the Austral summer of1998 in Northern Victoria Land (NVL), including Terra Nova Bay (TNB), Antarctica. Thelocations were selected according to the known Cenozoic fault framework that is characterizedby a system of NW-SE regional faults with right-lateral, strike-slip kinematics. The TNB1permanent GPS station is within the VLNDEF, and following its installation on a bedrockmonument in October 1998 it has been recording almost continuously. The GPS network hasbeen surveyed routinely every two summers, using high-quality, dual-frequency GPS receivers.In this study, we present the results of a distributed session approach applied to the processing ofthe GPS data of the VLNDEF. An improved reference frame definition was implemented,including a new Euler pole, to compute the Antarctic intra-plate residual velocities. Theprojection of the residual velocities on the main faults in NVL show present-day activities forsome faults, including the Tucker, Leap Year, Lanterman, Aviator, and David faults, with rightlateralstrike-slip kinematics and local extensional/ compressional components. This active faultpattern divides NVL into eight rigid blocks, each characterized by their relative movements andrigid rotations. These show velocities of up to several mm/yr, which are comparable to thosepredicted by plate tectonic theory at active plate margins.

2010 - Adjustment and transformation strategies of ItalPoS Permanent GNSS Network [Articolo su rivista]
Castagnetti, Cristina; Casula, Giuseppe; Capra, Alessandro; Bianchi, Maria Giovanna; Dubbini, Marco
abstract

A private network of 133 GNSS (Global Navigation Satellite Systems) permanent sites, named ItalPoS (Italian Positioning Service) and covering quite uniformly the entire Italian territory, was established since April 2006 by the Italian Division of Leica Geosystems S.p.A. This network involves also several GPS stations of the INGV (Italian National Institute of Geophysics and Volcanology) RING (Real-time Integrated National Gps) network and GPS stations from other public and private administrations. The purpose of ItalPoS network is mainly the GNSS data distribution in terms of real time corrections and RINEX files for the post-processing. In order to compute and distribute to private and scientific users a set of adjusted coordinates of the ItalPoS network in the IGS05 and ETRF89-ETRF2000 (European Terrestrial Reference Frame) reference frames, a dataset of RINEX (Receiver INdependent EXchange) of 133 GPS permanent sites was created and processed, using the distributed sessions approach, by means of Gamit/Globk 10.3 GPS data processor, using also some SOPAC (Scripps Orbit and Permanent Array Center) and EUREF (Reference Frame Sub Commission for Europe) solutions to improve the reference frame definition and the internal constraint. All the strategies adopted to estimate coordinates and velocities of the ItalPoS Network in IGS05 will be described together with the investigated approaches to provide coordinates in ETRF89-ETRF2000 reference frames: in this case both Helmert and Boucher-Altamimi transformations were taken into account, the whole Italian territory was divided into three parts in order to optimize transformation residuals. Particular attention was paid to transition areas.

2010 - GPS-Aided Land-Based Navigation and Precision Farming Applications: Improving GPS Solutions by Means of MEMS-IMU and Low-Cost Sensors [Relazione in Atti di Convegno]
Castagnetti, Cristina; Biagi, Ludovico; Capra, Alessandro
abstract

The land-based navigation, paying attention to precision farming, is the research topic: the final purpose is the design and development of a guidance-aided system focusing on a lew-cost GPS receiver able to provide a pseudorange-based solution only. Specific tests have been carried out to perform the particular trajectories followed by the vehicle in agricultural applications, whose accuracy target is typically 1 m. Results show that the low-cost receiver is affected by a drift in time which is mainly detected while turning and causing a deviation from the optimal reference solution. Thus, the goal is to correct this behaviour because the deviation accumulates during time and causes a not optimal treatment of the field (waste of material and money). Paying attention to the cost of the system, a new idea was proposed: the integration between the low-cost GPS with a magnetometer/digital compass. A dedicated algorithm was also implemented, taking the heading provided by the magnetometer and using it to correct the deviation in rums. Unluckily a magnetometer is deeply influenced by ferrous materials and the sensor is supposed to be installed on the vehicle, which is mainly made by metal. As a consequence, the sensed measurements are affected by a deviation from the actual magnetic field. Those disturbances need to be properly reduced by an autocalibration procedure. First of all, this paper deeply analyzes the performances of those particular low-cost GPS receivers; furthermore a solution is presented by means of the integration with a magnetometer. Results will be shown with great attention to future developments and improvements of the low-cost system suggested for supporting the guidance in precision farming applications.

2010 - Map updating and coastline control with very high resolution satellite images: application to Molise and Puglia coasts (Italy) [Articolo su rivista]
Bertacchini, Eleonora; Capra, Alessandro
abstract

The very high-resolution satellite images are a useful tool both for map updating and environmental monitoring. Phenomena, with a detail of 0.5m up to 1m, could be observed. The coastal areas are quite critical and quickly evolving. QuickBird and Ikonos images are likely able to investigate coastal changes within 1m of accuracy. This paper deals with two experiments applied to the coastline control: the first one concerns the study of Molise coasts, while the second is related to the Puglia Region map updating.

2010 - Monitoraggio “near real time” di rischio frane: un GIS per la gestione dell’emergenza. [Relazione in Atti di Convegno]
Bertacchini, Eleonora; Castagnetti, Cristina; Capra, Alessandro; Dubbini, Marco; Boni, Emanuele
abstract

La presente ricerca è stata condotta nell’ambito del progetto PRIN07 “Rilievo e analisi multi- temporale in un Sistema di Informazioni Geo-spaziali per il monitoraggio dei movimenti e delle deformazioni di aree soggette a rischio territoriale” ed anche nell’ambito di convenzioni stilate con il Servizio Tecnico di Bacino degli affluenti del Po, sede di Modena. L’obiettivo del lavoro è la realizzazione di un Sistema di Informazioni Geo-spaziali (GIS) per la valutazione e la gestione del monitoraggio di aree soggette a rischio frane basato su misure provenienti da molteplici strumentazioni (topografiche e geotecniche).L’area test, la frana dei Boschi di Valoria, ubicata a Frassinoro (MO), è stata utilizzata come caso di studio sia per dimensioni sia per entità dei movimenti, particolarmente elevati in fase di acuta riattivazione (spostamenti fino a 10m al giorno). La caratteristica principale del sistema è la multidisciplinarietà, l’integrazione di molteplici approcci che diventano vicendevolmente i protagonisti da cui estrarre informazioni a seconda del lettore interessato: l’area è stata studiata con varie tecnologie, quali tecniche di posizionamento satellitare (GPS - Global Positioning System), stazione totale automatizzata, rilievi laser scanner da aereo (voli LiDAR - Light Detection And Ranging), strumentazione geotecnica (estensimetri, piezometri, inclinometri) e radar interferometrico terrestre (GB Sar - Ground Based Sinthetic aperture radar). Avere a disposizione una tale mole di dati è certamente una condizione invidiabile, a patto che sia subordinata ad un’adeguata organizzazione della stessa, al fine di renderla fruibile e soprattutto rapidamente consultabile: si è deciso così di raccogliere e visualizzare il tutto in un GIS. E’ stata posta particolare attenzione alla modalità di aggiornamento del sistema, che dovrebbe essere visualizzabile quasi in tempo reale: dati provenienti dalla stazione totale robotizzata e dal GPS, in continua acquisizione in sito, devono essere resi disponibili e visibili agli organi competenti il prima possibile, in modo da permettere un efficace e rapido intervento in caso di eventi di una certa entità. Da questa necessità è nato il problema, che in un primo momento era sembrato banale, della georeferenziazione dei dati in pseudo real time: le misure in frana fatte dalla stazione totale e le posizioni calcolate dei prismi sono prodotte in un sistema locale, ma devono essere trasformate nel sistema ETRF2000 (European Terrestrial Reference Frame) per essere congruenti con quelle risultanti dai GPS rover posti in frana. Si aggiunge la necessità di trasformare tutto il database corrente in modo da sovrapporlo alla cartografia regionale, fornita in ED50 UTM* per l’Emilia Romagna. Il GIS realizzato può essere efficacemente preso in considerazione come strumento per la pianificazione e la gestione di situazioni di emergenza a seguito di eventi di disastro causati da fenomeni di dissesto idrogeologico (frane).251Atti 14a Conferenza Nazionale ASITA - Brescia 9-12 novembre 2010Abstract (English version)The research is included in the PRIN07 project -Multi-temporal surveying and analysis in Geo- spatial Information System for monitoring areas subject to landslide risk-. The final purpose is the design and implementation of a GIS (Geographic Information System) focused on landslides monitoring based on multiple technologies.The case study is the Valoria landslide, located in Frassinoro (Modena, Italy), which was chosen as test site both for its largeness and for considerable displacements detected during the re-activation (10 m/day). The main feature of this system is the integration of multiple and different approaches and technologies such as satellite-based positioning (GPS - Global Positioning System), automated total station, airborne laser scanner (LiDAR - Light Detection And Ranging), geotechnical instruments (extensometers, piezometers, inclinom

2010 - Structural analysis of the Ghirlandina Tower vertical displacements [Capitolo/Saggio]
Bertacchini, Eleonora; Capra, Alessandro; Castagnetti, Cristina; Dubbini, Marco; Boni, Emanuele
abstract

The paper deals with the subsidence monitoring in the monumental centre of Modena with particular attention to the structural consequences on the UNESCO site. High precision leveling campaigns have been carried out in Piazza Grande; the network measurements, the data processing and the results are deeply described along with the structural implications for the Ghirlandina tower.

2010 - Terrestrial Laser Scanner for Surveying and Monitoring Middle Age Towers [Relazione in Atti di Convegno]
Bertacchini, Eleonora; Boni, Emanuele; Capra, Alessandro; Castagnetti, Cristina; Dubbini, Marco
abstract

We had the opportunity to make surveying of some middle age towers located in Emilia Romagna region (Italy): Ghirlandina tower (Modena), “Della Sagra” tower (Carpi, Modena) , Asinelli tower (Bologna). Those towers are very interesting by architectural and artistic point of view; Ghirlandina and Asinelli are Cultural Heritage site of UNESCO.Terrestrial laser scanner (TLS) instrument has been used with an accuracy at 1 cm level in order to obtain good restitution in absolute coordinates, even with a precise topographic determination of GCP (Ground Control Points). Tridimensional restitution of the towers is here presented; we would like to point out the attention on the way that we use the TLS for enhancing the geometrical characteristics, particularly the height of the towers and the axis development that were determined through the trajectory of barycenter of transversal sections.The determination of actual geometry is essential for the study of the buildings and it is a first fundamental step for monitoring the towers.

2009 - Adjustment and transformation strategies of ItalPoS permanent GNSS network [Articolo su rivista]
Castagnetti, Cristina; Casula, Giuseppe; Dubbini, Marco; Capra, Alessandro
abstract

A private network of 133 Global Navigation Satellite Systems (GNSS) permanent sites, named ItalPoS (Italian Positioning Service) and covering quite uniformly the entire Italian territory, was established since April 2006 by the Italian Division of Leica Geosystems S.p.A. This network involves also several GPS stations of the INGV (Italian National Institute of Geophysics and Volcanology) RING (Real-time Integrated National Gps) network and GPS stations from other public and private administrations. Indeed Leica Geosystems contributed with its experience and its products to these networks which nowadays fulfill the national covering where there are no ItalPoS stations. For instance, the purpose of ItalPoS network is mainly the GNSS data distribution in terms of real time corrections and RINEX files for the post-processing.In order to compute and distribute to private and scientific users a set of adjusted coordinates of the ItalPoS network in the IGS05 and ETRF89-2000 reference frames, a dataset of RINEX of about 120 GPS permanent sites was created and processed, using the distributed sessions approach, by means of Gamit/Globk 10.3 GPS data processor, using also some SOPAC (Scripps Orbits and Permanent Array Center) and EUREF (European Permanent Network) solutions to improve the reference frame definition and the internal constraint.In this paper we describe all the strategies adopted to estimate coordinates and velocities of the ItalPoS Network in IGS05 and in ETRF89-2000 reference frames in the whole Italian territory.

2009 - Applied Geomatics [Direzione o Responsabilità Riviste]
Capra, Alessandro
abstract

2009 - Continuous monitoring of active earth flow by means of an integrated GPS-automatic total station approach [Articolo su rivista]
Corsini, A.; Capra, A.; Bertacchini, E; Borgatti, L.; Borghi, A.; Castagnetti, Cristina; Cervi, F.; Daehne, A.; Dubb Ini, M.; Leuratti, E.; Manzi, V.; Pellegrini, M.; Ronchetti, F.; Bonanno, C.; Piantelli, E.
abstract

The research deals with the integration of surface displacement measurements obtained using geodetic and topographic instruments such as GPS, automatic total station and inclinometer sensor in a large-scale active earth flow. The landslide, located in the northern Apennine of Italy, damaged roads and endangered houses during a sequence of reactivations in 2001, 2005 and 2007. Monitoring has been performed by means of: an automatic total station, coupled with inclinometer sensor, measuring about 40 prisms located in the landslide to a maximum distance of 1.650 km; one double-frequency GPS receiver connects in streaming by wireless communication with 4 single-frequency GPS in side the flow. Until December 2007 the monitoring network was operated with periodic static surveyings followed by the data post-processing; while since March 2008 the total station system and GPS were automated in order to allow continuous data acquisition and near-real-time data processing. The monitoring network has been able to cope with displacement rates ranging from millimetres to metres per day, a performance not achieved by borehole systems operated in the slope, such as in-place inclinometers, that were damaged when displacements exceeded some decimetres. The data so far collected, integrated with geomorphic, geologic and borehole data, allowed the complex spatial and temporal pattern of slope movements to be tracked and the relationships between rainfall pattern and acceleration-deceleration phases to be highlighted.

2009 - Densification of IGS/EPN by local permanent networks: results sensitivity with respect to the adjustments choices [Articolo su rivista]
Biagi, Ludovico; Caldera, Stefano; Sansò, Fernando; Capra, Alessandro; Castagnetti, Cristina
abstract

The paper describes the processing strategies experienced in dealing with GNSS permanent network. Particularly the choices for the adjustment of IGS and EPN network densification concerning the case of Puglia and Lombardia italian regions.

2009 - Fotogrammetria per l'archeologia [Capitolo/Saggio]
M., Dubbini; Capra, Alessandro
abstract

Volume GROMA 2 . In profondità senza scavare- Metodologie di indagine non invasiva e diagnostica per l'archeologia.Uno ei capitoli sul rilievo per l'archeologia; in particolare si tratta della Fotogrammetria applicata all'archeologia.

2009 - GNSS (Global Navigation Satellite Suystem) [Capitolo/Saggio]
Capra, Alessandro; M., Dubbini; E., Giorgi
abstract

In profondità senza scavare. Metodologie non invasive e diagnostica per l'archeologia.Metodi e strumenti per il rilievo applicato all'archeologia; in particolare il sistema GNSS per l'archeologia.

2009 - I dati del monitoraggio per la comprensione dei movimenti della torre Ghirlandina.The role of monitoring Tower movements [Capitolo/Saggio]
C., Blasi; Capra, Alessandro; E., Coisson; R., Lancellotta
abstract

La torre Ghirlandina. Un progetto di conservazione. Nell'ambito della sezione sugli studi della sturttura, vengono presentati i risultati delle attiviità di monitoraggio della Torre.The Ghirlandina tower. Within the section "The Structure", the monitoringactivity is shown.

2009 - Il rilevamento della torre Ghirlandina.The surveying of Ghirlandina tower. [Capitolo/Saggio]
P., Giandebiaggi; A., Zerbi; Capra, Alessandro
abstract

La torre Ghirlandina. Nell'ambito della sezione "La conoscenza" vengono presentati i risultati del rilevamento della torre.The Ghirlandina tower. Within the section "The knowledge", results of tower surveying are shown.

2009 - Il ruolo delle tecnologia nella formazione dell'archeologo. Un approccio diverso. [Capitolo/Saggio]
Capra, Alessandro
abstract

GROMA 2 - In profondità senza scavare. Metodologie non invasive e diagnostica per l'archeologia.Intervento alla tavola rotonda sul tema del ruolo delle tecnologia nella formazione dell'archeologo.

2009 - Imaging of the Antarctic ionosphere: Experimental results [Articolo su rivista]
P., Yin; Mitchell, C. N.; L., Alfonsi; M., Pinnock; P., Spencer; G., De Franceschi; V., Romano; P., Newell; P., Sarti; M., Negusini; Capra, Alessandro
abstract

Ground-based dual-frequency GPS observations can be used to create images of electron density. This is well established for the Arctic ionosphere; here one of the first results is presented for the Antarctic. In this study, the GPS receivers in the Antarctic are supplemented with another GPS receiver onboard CHAMP. The aim of the study is to demonstrate the technique for investigating geophysical events, for example, an ionospheric disturbance period on 11 February 2004. The images have been validated by in-situ measurements from DMSP and CHAMP satellites, as well as Super Dual Auroral Radar Network (SuperDARN) convection patterns, which are able to confirm the location, presence, and transportation of large-scale plasma patches. This study indicates that although the convection still dominates in the high-latitude ionosphere, soft precipitation within the polar cap may play a role in the evolution of the polar patches. It also illustrates the potential for future multi-instrument studies of the Antarctic. (C) 2009 Elsevier Ltd. All rights reserved.

2009 - Integrated Surveying System for Landslide Monitoring, Valoria Landslide (Appennines of Modena, Italy) [Relazione in Atti di Convegno]
Bertacchini, Eleonora; Capitani, Andrea; Capra, Alessandro; Castagnetti, Cristina; Corsini, Alessandro; Dubbini, Marco; Ronchetti, Francesco
abstract

The research object is the study and prevention of landslide risk through the utilization of integrated surveying systems like GPS and Automatic Total Station (Robotic station).The measurements have been applied to Boschi di Valoria landslide, located on Appennines of Modena in the Northern Italy, which relatively large size, about 1.6 square km, required the use of both techniques. The system is made by Automatic Total Station, looking at 45 reflectors and a GPS master station, reference for three rovers on the landslide. In order to monitor "local" disturbing effects, a bi-dimensional clinometer has been applied on the pilaster where the total station is located. In a first periodically measurements were collected, while the system is now performing continuously. The system permitted to evaluate movements from few millimeter till some meters per day in most dangerous areas; the entity of the movements obliged to plan an alert system that was activated after a first phase of phenomenon study. Topographic measurements have been integrated with geotechnical sensors (inclinometers and piezometers) in a GIS for landslide risk management.

2009 - Laser scanner terrestre [Capitolo/Saggio]
Capra, Alessandro; Dubbini, M.; Giorgi, E.
abstract

In profondità senza scavare. Metodi di indagine non invasiva e diagnostica per l'archeologia.Metodi e strumenti per il rilievo applicato all'archeologia; in particolare il rilievo laser scanner terrestre per l'archeologia.

2009 - Misure topografiche di precisione per il monitoraggio in zone a rischio idrogeologico [Articolo su rivista]
Bertacchini, Eleonora; Capra, Alessandro; Castagnetti, Cristina; Dubbini, Marco
abstract

L'articolo descrive una sperimentazione di strumentazione integrata in acquisizione periodica e successivamente continua per il monitoraggio del dissesto idrogeologico.

2009 - Stazione totale per il monitoraggio Leica TM30: test di verifica secondo norme DIN-18723 e test di funzionamento per il monitoraggio frane [Relazione in Atti di Convegno]
Bertacchini, E.; Boni, E.; Capitani, A.; Capra, A.; Castagnetti, C.; Corsini, A.; Dubbini, M.; Parmeggiani, E.
abstract

2009 - Valutazione dell'utilizzo dio immagini satellitari ad alta risoluzione Quickbird per l'aggiornamento del database topografico del SIT della regione Puglia [Relazione in Atti di Convegno]
Bertacchini, E.; Bellanova, A.; Capra, A.; Caroppo, T.
abstract

2008 - Geodetic and Geophysical Observations in Antarctica. An overview in IPY perspective [Monografia/Trattato scientifico]
Capra, Alessandro; R., Dietrich
abstract

The polar regions with their unique geophysical and geodynamic environment are characterized by close interactions between solid earth, cryosphere, hydrosphere and athmosphere. They are directly linked to the global climate system. Geodetic and geophysical observations play an essential role in the scientific investigation of the polar regions, especially with regard to permanent and temporary observatories. For several years geodetic observatories have been realized in Antarctica by continuous or periodic data acquisitions. The observation techniques include: Global Navigation Satellite Systems (GNSS, in particular GPS and GLONASS, in futre also GALILEO); further geodetic space techniques (DORIS, VLBI); tide gauges observations; absolute, tidal and relative gravimetry; seismology; geomagnetometry; meteorology.Within the Scientific Commettee on Antarctic Research (SCAR) the SCAR group of experts on Geodetic Infrastructure of Antarctica (GIANT) spent great effort to coordinate the international activities and to enhance the development of geodetic and geophysical observatories.In order to gain a better understanding of the polar environment long time series as recorded by permanent observatories should be integrated together with data acquired by field surveys like geological and glaciological sampling, geophysical investigations, and with satellite data (remote sensing, satellite gravimetry).Focussed on the geodetic-geodynamic aspects of the IPY project "Polar Earth Observing Network" (POLENET, IPY full proposal no. 185) special attention should be given to regional and global model generation and validation (regional geodynamics, plate tectonics, postglacial rebound, global climate system, global change).Special sessions at international symposia have been dedicated to Antarctic geodetic and geophysical observations and data analysis; among others we would like to mention Session G10 “Short and long-term observations in polar region” - EGU06, Vienna, April 2006; and the International Workshop “ GPS in the IPY: The POLENET Project” - Dresden, Germany, October 4-6, 2006. relevant contributions have been presented at the ISAES X (X. International Symposium on Antarctic Earth Science), Santa Barbara, California, USA, August 2007.The book is intended to give an overview on all aspects of the scientific utilization of geodetic-geophysical observations in Antarctica, of data analysis and geodynamic interpretation as well as of the various technological aspects in setting up autonomous observatories in Antarctica.

2008 - GPS navigation for precision farming [Relazione in Atti di Convegno]
Biagi, Ludovico; Capra, Alessandro; Castagnetti, Cristina; Dubbini, Marco; Unguendoli, Francesco
abstract

Precision farming, sometimes called site-specific agriculture, is a strategic task for agriculture: indeed it has the potential to reduce costs through more efficient and effective applications of crop inputs; it can also reduce environmental impacts by allowing farmers to apply inputs only where they are needed at the appropriate rate. Precision farming requires the use of new technologies, such as GPS, environmental sensors, satellites or aerial images and GIS to asses and understand variations. The present research deals with potentialities and limits of GPS for navigation in agricultural applications. GPS needs for farming applications are: − low cost in order to allow farmers to buy GPS technologies; −high precision in order to reduce the use of pesticides and fertilizers by means of an exact track. At first, static and kinematic tests have been performed, simulating the typical behaviour of an agricultural vehicle and usingdifferent kinds of GPS receivers and navigation softwares; the experimental results are presented: particularly, advantages and disadvantages of the popular Kalman filtering on trajectories are discussed. Starting from the analyses of the previous results, and taking into account the typical user requirements, a preliminary design for a new prototype has been done; particularly, both needed instrumentations and their costs and a proposal of a new navigation algorithm will be presented.

2008 - Inquadramento delle reti regionali VLNDEF e TAMDEF (Antartide) nel sistema di riferimento globale [Relazione in Atti di Convegno]
Capra, Alessandro; Galeandro, A; Mancini, Francesco; Negusini, M; Vittuari, L.
abstract

L’obiettivo del presente lavoro è di definire le strategie più opportune per l’inquadramento delle reti antartiche di stazioni permanenti ed episodiche in un sistema di riferimento globale. Lo studio è stato focalizzato in particolare sulla rete antartica di stazioni permanenti e sulle sottoreti regionali VLNDEF e TAMDEF, allo scopo di ottenere informazioni circa la cinematica superficiale della Terra Vittoria (Antartide). L’approccio scelto per l’inquadramento è stato sviluppato in tre fasi: inquadramento delle stazioni permanenti presenti nella regione oggetto di studio, connessione dei siti delle due reti regionali alle stazioni permanenti precedentemente inquadrate, elaborazione di tutte le informazioni a livello di equazioni normali. Per l’analisi dei dati è stato utilizzato il Bernese GPS software v5.0. Per l’elaborazione dei dati sono stati utilizzati parametri e modelli standard, eseguendo per alcuni di essi dei test per verificare quanto essi incidessero sull’analisi del dato e quali fossero le scelte migliori per la soluzione finale. L’analisi delle serie storiche ha evidenziato quali stazioni permanenti fossero affidabili per la connessione delle reti regionali. L’analisi spettrale delle stesse ha messo in rilievo la presenza di segnali periodici che influenzano la determinazione delle velocità, in particolar modo per la componente verticale. I risultati ottenuti mostrano un andamento ben determinato per quanto riguarda le velocità planimetriche, mentre, sono ancora incerte, in termini di spostamento verticale assoluto, a seconda del sistema di riferimento utilizzato, ITRF2000 o ITRF2005. Questo lascia ancora irrisolto il problema dell’interpretazione dei risultati da utilizzare come condizioni al contorno per i modelli geodinamici delle zone oggetto di studio.

2008 - Ortorettifica di immagini satellitari IKONOS della costa del Molise attraverso DLT [Relazione in Atti di Convegno]
Bertacchini, Eleonora; Capra, Alessandro; M., Dubbini; F:immordino,
abstract

Ortorettifica di immagini satellitari IKONOS della costa del Molise attraverso DLT

2008 - Vertical motions in Northern Victoria Land inferred from GPS: A comparison with a glacial isostatic adjustment model [Relazione in Atti di Convegno]
Mancini, Francesco; Negusini, M; Zanutta, A; Capra, Alessandro
abstract

Recent development of italian geodetic reseacrh related to the comparison of defromation obtained with GPS measurements with data obtained from GIA models

2008 - VLNDEF project for Geodetic Infrastructure definition of northern Vicotoria Land, Antarctica [Capitolo/Saggio]
Capra, Alessandro; M., Dubbini; A., Galeandro; L., Gusella; A., Zanutta; G., Casula; M., Negusini; L., Vittuari; P., Sarti; F., Mancini; S., Gandolfi; S., Montaguti; G., Bitelli
abstract

Scientific investigations in Antarctica are, for many different reasons, a challenging and fascinating task. Measurements, observations and field operations must be carefully planned well in advance and the capacity of successfully meeting the goals of a scientific project is often related to the capacity of forecasting and anticipating the many different potential mishaps. In order to do that, experience and logistic support are crucial. On the scientific side, the team must be aware of its tasks and be prepared to carry out observations in a hostile environment: both technology and human resources have to be suitably selected, prepared, tested and trained. On the logistic side, nations, institutions and any other organisation involved in the expeditions must ensure the proper amount of competence and practical support.The history of modern Italian Antarctic expeditions dates back to the middle 80’s when the first infrastructures of “Mario Zucchelli Station”, formerly Terra Nova Bay Station, were settled at Terra Nova Bay, Northern Victoria Land. Only a few years later, the first geodetic infrastructures were planned and built. Italian geodetic facilities and activities were, ever since, being constantly maintained and developed. Nowadays, the most remarkable geodetic infrastructures are the permanent Global Positioning System (GPS) station (TNB1) installed at Mario Zucchelli and the GPS geodetic network Victoria Land Network for DEFormation control (VLNDEF) entirely deployed on an area extending between 71° S and 76° S and 160° E and 170° E.These facilities do not only allow carrying out utmost geodetic investigations but also posses interesting capacities on the international multidisciplinary scientific scenario.In order to fully exploit their potentiality, management and maintenance of the infrastructure are crucial; nevertheless, in order to perform high quality scientific research, these abilities must be coupled with the knowledge concerning a proper use and a correct processing of the information that these infrastructures can provide.This work focuses on the different methods that can be applied to process the observations that are performed with GPS technique in Northern Victoria Land, aiming at reaching the highest accuracy of results and assuring the larger significance and versatility of the processing outcomes. Three software were used for the analysis, namely: Bernese v.5.0, Gipsy/Oasis II and Gamit/Globk. The working data sets are (i) the permanent GPS station TNB1 observations continuously performed since 1998 and (ii) the five episodic campaigns performed on the sites of VLNDEF.The two infrastructures can be regarded as neat examples of standard geodetic installation in Antarctica. Therefore, the technological solutions that were adopted and applied for establishing the GPS permanent station and the VLNDEF geodetic network as well as the data processing strategies and the data analysis procedures that were tested on their observation will be illustrated in detail. The results will be presented, compared and discussed. Furthermore, their potentials and role in geodetic research will be carefully described; their versatility will also be highlighted in the foreground of a multidisciplinary Antarctic international scientific activity.

2008 - VLNDEF Project for Geodetic Infrastructure Definition of Northern Victoria Land, Antarctica [Capitolo/Saggio]
Capra, Alessandro; Dubbini, M; Galeandro, A; Gusella, L; Zanutta, A; Casula, G; Negusini, M; Vittuari, L; Sarti, P; Mancini, Francesco; Gandolfi, S; Montaguti, S; Bitelli, G.
abstract

Scientific investigations in Antarctica are, for many different reasons, a challenging and fascinating task. Measurements, observations and field operations must be carefully planned well in advance and the capacity of successfully meeting the goals of a scientific project is often related to the capacity of forecasting and anticipating the many different potential mishaps. In order to do that, experience and logistic support are crucial. On the scientific side, the team must be aware of its tasks and be prepared to carry out observations in a hostile environment: both technology and human resources have to be suitably selected, prepared, tested and trained. On the logistic side, nations, institutions and any other organisation involved in the expeditions must ensure the proper amount of competence and practical support. The history of modern Italian Antarctic expeditions dates back to the middle 80’s when the first infrastructures of “Mario Zucchelli Station”, formerly Terra Nova Bay Station, were settled at Terra Nova Bay, Northern Victoria Land. Only a few years later, the first geodetic infrastructures were planned and built. Italian geodetic facilities and activities were, ever since, being constantly maintained and developed. Nowadays, the most remarkable geodetic infrastructures are the permanent Global Positioning System (GPS) station (TNB1) installed at Mario Zucchelli and the GPS geodetic network Victoria Land Network for DEFormation control (VLNDEF) entirely deployed on an area extending between 71◦S and 76◦S and 160◦E and 170◦E. These facilities do not only allow carrying out utmost geodetic investigations but also posses interesting capacities on the international multidisciplinary scientific scenario. In order to fully exploit their potentiality, management and maintenance of the infrastructure are crucial; nevertheless, in order to perform high quality scientific research, these abilities must be coupled with the knowledge concerning a proper use and a correct processing of the information that these infrastructures can provide. This work focuses on the different methods that can be applied to process the observations that are performed with GPS technique in Northern Victoria Land, aiming at reaching the highest accuracy of results and assuring the larger significance and versatility of the processing outcomes. Three software were used for the analysis, namely: Bernese v.5.0, Gipsy/Oasis II and Gamit/Globk. The working data sets are (i) the permanent GPS station TNB1 observations continuously performed since 1998 and (ii) the five episodic campaigns performed on the sites of VLNDEF. The two infrastructures can be regarded as neat examples of standard geodetic installation in Antarctica. Therefore, the technological solutions that were adopted and applied for establishing the GPS permanent station and the VLNDEF geodetic network as well as the data processing strategies and the data analysis procedures that were tested on their observation will be illustrated in detail. The results will be presented, compared and discussed. Furthermore, their potentials and role in geodetic research will be carefully described; their versatility will also be highlighted in the foreground of a multidisciplinary Antarctic international scientific activity.

2007 - Agricoltura di precisione:l'aiuto del GPS nella guida dei veicoli [Relazione in Atti di Convegno]
Biagi, L.; Capra, A.; Castagnetti, C.; Dubbini, M. Unguendopli F.
abstract

2007 - Analisi dei dati ASTER per la mappatura dei suoli e della temperatura superificiale nella Provincia di Taranto [Articolo su rivista]
M. G., Angelini; Capra, Alessandro; F., Immordino
abstract

Nella presente nota si descrive lo studio, in atto, su immagini satellitari ad alta risoluzione del sensore ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer).La ricerca si basa su analisi di carattere ambientale mediante l’interpretazione di dati digitali satellitari, per la stesura di mappe tematiche relative alla distribuzione della LST (Land Surface Temperature), ovvero delle anomalie termiche, nonché all’uso del suolo, alle dinamiche di trasformazione del suolo, ecc..

2007 - Geomatica [Monografia/Trattato scientifico]
Capra, Alessandro; D., Costantino
abstract

Testo ad uso didattico per corsi di Laurea e Laurea Magistrale in Ingegneria.

2007 - GPS as a geodetic tool for geodynamics in northern Victoria Land, Antarctica [Articolo su rivista]
Capra, A.; Mancini, F.; Negusini, M.
abstract

The VLNDEF (Victoria Land Network for DEFormation control) project started in 1999 with the aim of detecting crustal deformation in Northern Victoria Land (Antarctica) over an area that had never been surveyed by a dense GPS network before. After a brief summary of the Italian geodetic activities carried out since 1991, the paper presents the results obtained from the processing of data collected from 1999 to 2003. In particular, processing strategies were dealt with, in order to produce horizontal and vertical displacement maps through GPS observations. Absolute motions in a global reference frame have been investigated using a double approach, which allowed us to make considerable progress in detecting movements and standardizing the data analysis. The analyses provide absolute horizontal velocities ranging between 17 mm yr(-1) and 8 mm yr(-1), with greater motions in the northernmost area. The subtraction of the rigid plate motion provides relative displacements, which may contribute to the understanding of neotectonics and geology, whereas the pattern of the vertical crustal motions detected, with average values of +1.3 mm yr(-1), is essential to detect the effect of Glacial Isostatic Adjustment (GIA) and other geophysical signals, and to redefine theory and numerical models used without any direct measurements.

2007 - Il servizio di posizionamento GNSS per la regione Puglia [Relazione in Atti di Convegno]
Biagi, L.; Capra, A.; Castagnetti, C.; Caroppo, T.; Muschitiello, M.; Beallanova, A.; Galeandro, A.
abstract

2006 - Overview of geodetic reference frame and related activities in Antarctica [Articolo su rivista]
Capra, A.
abstract

Significative effort has been done within the Antarctic geodetic community to establish a reference system at continental scale. GIANT (Geodetic Infrastructure for ANTarctica) is being promoted within SCAR in order to unite researchers from different countries in an effort to produce a unique homogeneous set of geodetic observations. The SCAR GPS epoch campaigns project developed a GPS network of measurements. Geodetic observations collected continuously or during episodic campaigns are integrated with global observations in order to determine station coordinates in the International Terrestrial Reference Frame, ITRF. A short summary of some of the latest geodetic activities for Antarctic reference system establishment are described.

2006 - Overview of Geodetic Refrence Frame and Related Activities in Antartica [Articolo su rivista]
Capra, Alessandro
abstract

Significative effort has been done within the Antarctic geodetic community to establish a reference system at continental scale. GIANT (Geodetic Infrastructure for ANTarctica) is being promoted within SCAR in order to unite researchers from different countries in an effort to produce a unique homogeneous set of geodetic observations. The SCAR GPS epoch campaigns project developed a GPS network of measurements. Geodetic observations collected continuously or during episodic campaigns are integrated with global observations in order to determine station coordinates in the International Terrestrial Reference Frame, ITRF. A short summary of some of the latest geodetic activities for Antarctic reference system establishment are described.

2006 - Processamento di scene satellitari ASTER per la caratterizzazione dell’area Antartica di Baia Terra Nova [Altro]
Bellanova, A.; Angelini, M. G.; Capra, A.; Immordino, F.; Mancini, F.
abstract

2006 - Studi sul dato termico ASTER per applicazioni ambientali e territoriali [Relazione in Atti di Convegno]
ANGELINI M., G; Capra, Alessandro; DE GIGLIO, M; Immordino, F.
abstract

Studi sul dato termico ASTER per applicazioni ambientali e territoriali

2006 - Tecnica speditiva di stima del geoide a scala locale [Relazione in Atti di Convegno]
ANGELINI M., G; Bellanova, A; Capra, Alessandro; Costantino, D; Galeandro, A.
abstract

Tecnica speditiva di stima del geoide a scala locale

2006 - Variazione dell’uso del suolo da dati ASTER nella piana costiera ionica [Relazione in Atti di Convegno]
Angelini, M. G.; Capra, A; Immordino, F.; Bellanova, A.
abstract

2005 - Analisi delle deformazioni crostali dell’area dell’arco ionico tarantino [Relazione in Atti di Convegno]
Galeandro, A; Capra, Alessandro; Costantino, D.
abstract

Analisi delle deformazioni crostali dell’area dell’arco ionico tarantino

2005 - Deformazioni orizzontali verticali della Terra Vittoria Settentrionale, Antartide [Relazione in Atti di Convegno]
Capra, A.; Dubbini, M.; Mancini, F.; Montaguti, S.; Negusini, M.; Vittuari, L.; Zanutta, A.
abstract

2005 - Survey and 3D modelling of Castel del Monte [Relazione in Atti di Convegno]
Angelini, M. G.; Capra, Alessandro; Costantino, D.; Leserri, M.; Rossi, G.
abstract

Castel del Monte, symbol and emblem of the buildings Federico II architecture, seems has been realized for wish of the same Federico II on 1240. In 1876 the castle has been acquired by the Italian State and numerous interventions of restauration have been take. From 1996 Castel del Monte has been inserted by the UNESCO in the worldwide patrimony of the humanity for his oneness and it’s currently the monument more visited of Puglia.Numerous and rather fanciful hypotheses have been argued around original destination; such as many have been the interpretations around the octagonal matrix of the castle and the number eight, recognizing in these elements magic, ancestral, esoteric, astronomic references; by according to some researchers, the castle would have even hosted the Saint Graal. The originality of the site has induced a surveying more deepened through laser scanner technique, for the complexity of the structure, it was to plan a simulation of surveying steps.The above mentioned phases have allowed one more expeditious activity of survey; particularly the laser scanners survey have allowed a 3D model that could allow to verify different hypotheses or to formulate new one.

2005 - Terra Nova Bay GPS permanent station (Antarctica): data quality and first attempt in the evaluation of regional displacement [Articolo su rivista]
Negusini, M; Mancini, Francesco; Gandolfi, S; Capra, Alessandro
abstract

The paper discusses the long time series analysis of GPS permanent station located at Terra Nova Bay, East Antarctica (Victoria Land). The station (TNB1) was monumented during the 1997–1998 Italian expedition in Antarctica and the data collection started on January 1998. TNB1 is included in the Victoria Land network for deformation control (VLNDEF) network that was established with the aim to study the horizontal and vertical displacements in the region. The good-quality data obtained from this station allow the computation of long time series performed both by using a network approach with Bernese V4.2, and precise point positioning technique with GIPSY–OASIS II. In a first step, a subset of data was analysed to define the best processing strategy. Moreover, in the network approach, international GPS service (IGS) permanent stations (intra- and extra-plate) were used. Results obtained from the two approaches are comparable in terms of both repeatability and linear trend. Finally, velocities estimated for all Antarctic stations were compared to the values provided by ITRF2000. In most cases horizontal velocities agree with the model, while significant differences are present along the vertical components.

2005 - Virtual reconstruction of damaged decorative elements [Relazione in Atti di Convegno]
ANGELINI M., G; Capra, Alessandro; Costantino, D.
abstract

Surveying technoques to have a 3D restitution of a damaged decorative elements in order to furnish geometrical informations for a successive reastauraton activity.Proceedings su CD-rom

2004 - Il rilievo e la restituzione di strutture sommerse- esempi di strutture in mare e in fiume. Presentazione inaugurale mostra Relitti dal mare, Metodi e applicazione del rilievo archeologico subacqueo. Inaugurazione del Museo della Marineria di Cesenatico, 19 Giugno 2004 [Mostra]
Capra, A
abstract

2004 - La tecnica laser scanner applicata a siti archeologici e architettonici [Relazione in Atti di Convegno]
M. G., Angelini; Capra, Alessandro; D., Costantino
abstract

La tecnica laser scanner applicata a siti archeologici e architettonici

2004 - Metodi di rilievo applicati a Chiese rupestri: Chiesa di Lama D’Antico [Relazione in Atti di Convegno]
Angelini, M. G.; Capra, A; DI SANTE, Costantino; Galeandro, A; Putignano, E.; Todaro, S.
abstract

2004 - Space Geodesy as a tool for measuring ice surface velocity in the Dome C region and along the ITASE traverse. [Articolo su rivista]
L., Vittuari; C., Vincent; M., Frezzotti; S., Gandolfi; G., Bitelli; CAPRA, Alessandro; MANCINI, Francesco
abstract

Dome C was chosen by the European Project for Ice Coring in Antarctica (EPICA) as the site for the drilling of a deep ice core. This paper presents results from geodetic surveys of ice velocities (absolute and relative) at Dome C and along a transect to Terra Nova Bay. The purpose of the surveys was to provide accurate data for the study of ice dynamics, particularly a strain network comprising 37 poles surveyed in 1995 and again in 1999. Data indicate that the ice surface at the poles closest to the topographic summit moves horizontally by up to a few mm a−1 in a direction consistent with downslope motion of the ice sheet, while 25 km from the summit it moves up to 211 mm a−1. The EPICA drilling site yields an interpolated velocity of about 15 ± 10 mm a−1 in a north-northwesterly direction. Analysis of the velocity field and surface topography reveals that the surface flow centre is nearly co-located with the dome summit, and that both are in a steady-state condition. The measured horizontal velocities are consistent with the remote-sensing result and provide accurate ground-truth control for flow mapping. Seven snow–firn cores, up to 53 m deep, were drilled during the Terra Nova Bay–Dome C traverse. Submerged velocity systems were installed at the borehole and measured using the global positioning system (GPS). First results show a steady-state condition. Measured (horizontal) ice velocities increase from the summit of the ice sheet to the coast, reaching about 28 m a−1 at site GPS2A.

2004 - Utilizzo e finalità della stazione GPS permanente di Taranto [Relazione in Atti di Convegno]
Capra, Alessandro; D., Costantino; A., Galeandro
abstract

Utilizzo e finalità della stazione GPS permanente di Taranto

2004 - VLNDEF (Victoria Land Network for DEFormation control). Monumentation during the GANOVEX VIII – ITALIANTARTIDE XV: Survey and Data Processing [Articolo su rivista]
Mancini, F; Capra, A; Gandolfi, S; Sarti, P; Vittuari, Luca
abstract

In the frame of the 1999-2000 Italian expedition in Antarctica a scientific programme for geodynamic purposes in the northern Victoria Land begun. The new project VLNDEF (Victoria Land Network for DEFormation control) deals with the monitoring of crustal deformations within the investigated area. The newly-monumented GPS stations and the following field geodetic surveys (hereafter discussed) extended an existing GPS geodetic network located close to the area of Terra Nova Bay where a GPS Permanent Station is also available. At the end of XV Italian expedition the network covered an area included between the latitude of 71 and 74.5 degrees South and longitude ranging between 160 and 170 degrees East (Capra et al., 2000). Later on, in the frame of the 2000-2001 expedition, the network was extended as far as latitude of 76 degrees South, with the monumentation of the southernmost points. Activities and results of the latter are not reported in this paper. The extension of the monumented network needed of operations carried out both from the research vessel Polar Duke employed by the expedition (points located at north of the 72th south parallel) and from the Italian Mario Zucchelli Station at Terra Nova Bay (all the remaining southern points). This paper deals with the field operations and survey carried out within the joint German-Italian Antarctic expedition 1999-2000 (Mancini, 2001). Results, accuracies, problem related to the reference frame and possibility to detect deformations by further investigation will be discussed. VLNDEF is a project within the activities of GIANT (Geodetic Infrastructure of ANTarctica) SCAR (Scientific Committee on Antarctic Research) programme and is supervised by the SCAR group of specialists of ANTEC (Antarctic NeoTECtonics).

2003 - Analisi preliminare delle deformazioni dell’area dell’arco ionico-tarantino [Relazione in Atti di Convegno]
Capra, Alessandro; Costantino, D.; Galeandro, A.
abstract

Analisi preliminare delle deformazioni dell’area dell’arco ionico-tarantino

2003 - Applicazioni di fotogrammetria e laser scanner terrestre alle colonne del tempio di Poseidone, Taranto. [Relazione in Atti di Convegno]
Capra, Alessandro; D., Costantino; R., Maggi
abstract

Applicazioni di fotogrammetria e laser scanner terrestre alle colonne del tempio di Poseidone, Taranto.

2003 - Il GIS come strumento per la caratterizzazione spazio temporale, la gestione e la manutenzione di una rete tecnologica [Relazione in Atti di Convegno]
Capra, Alessandro; D., Costantino; G., Angelini
abstract

Il GIS come strumento per la caratterizzazione spazio temporale, la gestione e la manutenzione di una rete tecnologica

2003 - Il progetto VLNDEF per il monitoraggio delle deformazioni crostali della Terra Vittoria settentrionale. [Relazione in Atti di Convegno]
Capra, A.; Gandolfi, S.; Mancini, F.; Vittuari, L.; Bitelli, G.; Sarti, P.; Zanutta, A.
abstract

2003 - La georeferenziazione delle immagini cartografiche e telerilevate [Relazione in Atti di Convegno]
Capra, Alessandro; D., Costantino; S., Todaro
abstract

La georeferenziazione delle immagini cartografiche e telerilevate

2003 - Terra Nova Bay GPS permanent station [Articolo su rivista]
Capra, A.; Gandolfi, S.; Mancini, F.; Negusini, M.; Sarti, P.; Vittuari, L.
abstract

During the IV Italian expedition in Antarctica, the geodetic activity started with the installation of the geodetic network in the area of Terra Nova Bay. The network was established in order to provide a common reference frame to several scientific activities (photogrammetry, cartography, geology) and to study the geodynamics of an area including some interesting tectonic and geologic features. The TNB1 (official name) GPS permanent station was installed during the XIII Italian expedition in 1998, over a granitic hill close to the Italian station of Terra Nova Bay. Following the recommendations for a stable and well-suited site location for the GPS permanent station a concrete-made pillar was monumented in an area far away from radio frequency disturbs which also guaranteed a complete satellite visibility. The location of the GPS permanent station site with respect to Terra Nova Bay station and a particular of the monumentation are shown in figure 1. The geographic location of Terra Nova Bay covered a gap in the distribution of GPS permanent stations in East Antarctica and, more precisely, along northern Victoria Land. Fifteen GPS permanent stations have been installed in Antarctica until today, and seven of them are IGS (International GPS Service for Geo-dynamics) stations. The non-homogeneous geographic distribution of stations, the long distances involved and their prevalent settlement on the coastal area leads to some difficulties in a precise satellite ephemeris determination and in GPS data processing for regional geodynamic purposes phenomena with an accuracy at the 5 mm level achieved in static relative positioning.

2002 - Analysis of Regional Geoid Estimation in Victoria Land. [Relazione in Atti di Convegno]
Barzaghi, R.; Borghi, A.; Capra, A.; Gandolfi, S.
abstract

2002 - Cartografia dell’Isola di Canopo [Capitolo/Saggio]
Capra, Alessandro
abstract

Rilievo GPs cinematico per realizzatre il DTM dell'Isola di Canopo. Realizzazione di una cartogarfia a grande scala di un'area non cartografta alla scala di riferimento, importante per le operazioni di studio e scavo archeologico.

2002 - CONTROLLO DELLE DEFORMAZIONI CROSTALI DELL’AREA DEL MAR PICCOLO E DELLE MURGE [Relazione in Atti di Convegno]
Capra, Alessandro; D., Costantino; V., Simeone
abstract

CONTROLLO DELLE DEFORMAZIONI CROSTALI DELL’AREA DEL MAR PICCOLO E DELLE MURGE

2002 - Digital photogrammetry and laser scanning in surveying the “Nymphaea” in Pompeii [Relazione in Atti di Convegno]
Bitelli, G.; Capra, A.; Zanutta, A.
abstract

2002 - Geophysical feature of the Mt. Melbourne Area, Antarctica, and preliminary results from the integrated network for monitoring the volcano [Relazione in Atti di Convegno]
Armadillo, E; Bonaccorso, A; Caneva, G; Capra, Alessandro; Falzone, P; Ferraccioli, F; Mancini, Francesco; Privitera, E; Vittuari, L.
abstract

Geophysical features of the Mt. Melbourne area and first results from the integrated network for monitoring the volcano (Antarctica)

2002 - La rete GPS per il controllo delle deformazioni nell’area di Baia Terra Nova (Antartide) [Relazione in Atti di Convegno]
Capra, A.; Gandolfi, S.; Mancini, F.; Sarti, P.; Vittuari, L.
abstract

2002 - Metodo GPS e rilievo archeologico. Definizione di una superficie di riferimento per la realizzazione di un GIS su alcuni siti della valle di Chacas (Perù) [Articolo su rivista]
Capra, Alessandro; Laurencich, L; Mancini, Francesco; Orsini, C.
abstract

The Chacas Valley Project (Dep. of Ancash, Peru), coordinated by Prof. Laurencich Minelli of University of Bologna, is a partnership between the Ministry of Foreign Affairs, the over mentioned University and the Municipality of Chacas. The aim of such project is to carry out an archaeological and anthropological survey on pre-Columbian cultures of the valley. The collected data will be the base for planning some trekking route between the archaeological sites. In lack of sufficiently detailed maps, it has been necessary to define a cartographic reference system to cover all the investigated area. The knowledge of a detailed topographical surface is also crucial to build up an architectural model of the pre-Columbian urbanized areas. Consequently, the definition of this surface is necessary to locate the architectonic structures and to define their destination of use, and also to investigate the relationship between the architecture and the morphology of the landscape, a very important element in the urbanization system of pre-Columbian civilizations. Such information will be obviously of primary importance in order to define some tourist trekking paths between the archaeological zones. This paper introduce the topographic survey carried out in two archaeological expeditions (1998 and 2000) on the fortified Recuay citadels (II-VI sec. a.d.) Huacramarca and Riway. During the first expedition a traditional methodology has been applied while in the second one a relative kinematic satellite GPS (Global Positioning System) methodology was employed. The high productivity of the gps methodology allows to acquire many information in short time, also working in difficult situations (the over mentioned citadels are located at 4000 mt above m.s.l. In a very distant position from the nearest villages). Through gps survey was possible to perform at the same time a survey to define the position of archaeological structures and the morphology of the landscape. This methodology, which allows the space referencing of all the objects and the integrated analysis of the information, is a very powerful tool for the interpretation of the sites. The recollected data could constitute the first step towards the realization of a gis for the cultural heritage valorization of this area, and offer a research opportunity for archaeologist to gather geo-morphological information together with all the other data available from different source of observation.

2002 - Multidisciplinary approach for archaeological survey: exploring GPS method for space related interpretation [Articolo su rivista]
Capra, Alessandro; Gandolfi, S; Laurencich, L; Mancini, Francesco; Minelli, A; Orsini, C; Rodriguez, Ar
abstract

Started in 1996, the Chacas Valley Project is coordinated by Laura Laurencich Minelli and aims to study the social–cultural organization of space in the Chacas Region (Ancash-Perú) during the Early Intermediate Period (III–VII century A.D.). For an anthropological interpretation of ancient urbanized territory, a multidisciplinary approach focused on gathering both archeological data and topographical information is necessary. The kinematic GPS method has been applied in order to reach the needed accuracy in representing the geometric properties of the objects, to preserve the geometric properties between the structures and to document the relations with the ground morphological aspects.

2002 - Multidsciplinary approach for archaeological survey: exploring GPS method in landscape archeology studies. Journal of Cultural Heritage, [Articolo su rivista]
Capra, Alessandro; S:, Gandolfi; L., Laurencich; F., Mancini; A., Minelli; C., Orsini; A. R., Rodriguez
abstract

Surveying of archaeological sites of Riway and Hucramarca (Perù) with GPS, photogrammetry and total station.Data Integration and results implemented in a GIS.

2002 - The Frontier Mountain meteorite gap (Antarctica) [Articolo su rivista]
L., Folco; Capra, Alessandro; M., Chiapini; M., Frezzotti; M., Mellini; I. E., Tabacco
abstract

The Frontier Mountain blue ice field is an important Antarctic meteorite trap which has yielded 472 meteorite specimens since its discovery in 1984. Remote sensing analyses and field campaigns from 1993 to 1999 have furnished new glaciological data on ice flow, ice thickness, bedrock topography, ice ablation and surface mass transport by wind, along with detailed descriptions of the field situation at the trap. This solid set of data combined with an updated meteorite distribution map and terrestrial ages available from literature allows us to better describe the nature of the concentration mechanism. In particular, we observe that the meteorite trap forms in a blue ice field i) located upstream of an absolute and a shallow subice barriers; ii) characterized by compressive ice flow with horizontal velocities decreasing from 100 to <10 cm a-1 on approaching the obstacle; iii) undergoing mean ablation rates of 6.5 cm a-1; iv) nourished by a limited snow accumulation zone extending ~20 km upstream of the blue ice area. We also draw the following conclusions: i) the origin of the meteorite trap can be explained according to the present-day glaciological situation; ii) the meteorite concentration develops according to the general principles of the “ice flow model”; iii) the accumulation model can be described as “stagnant ice or slow-moving ice against an absolute and submerged barriers”, according to the descriptive schemes present in literature; iv) the Frontier Mountain ice field is an effective trap for meteorites weighing more than ~200 g; for smaller masses, the combination of wind and glacial drift may remove meteorites in less than a few tens of ka; v) although the activation age of the FM trap is not yet constrained, we infer that one of the most important findsite may be as old as 50 ka, i.e. older than the Last Glacial Maximum.

2001 - Controllo delle deformazioni dell’ospedale Ss. Annunziata con metodologia tradizionale e GPS [Relazione in Atti di Convegno]
Capra, Alessandro; Costantino, D.
abstract

Controllo delle deformazioni dell’ospedale Ss. Annunziata con metodologia tradizionale e GPS

2001 - Il controllo delle deformazioni nell’area geotermica di Travale [Relazione in Atti di Convegno]
Capra, Alessandro; Gandolfi, S; Mancini, Francesco; Rossi, A; Vittuari, L.
abstract

Il controllo delle deformazioni nell’area geotermica di Travale

2001 - Immagini telrilevate ad alta risoluzione per l’aggiornamento cartografico. [Relazione in Atti di Convegno]
Capra, Alessandro; Caprioli, M.; Costantino, D.; Daddabbo, A.; Galiardi, S.; Tarantino, C.
abstract

Immagini telrilevate ad alta risoluzione per l’aggiornamento cartografico.

2001 - Rilievo e rappresentazione digitale dei siti archeologici dell’isola di Nelson (Alessandria, Egitto). [Capitolo/Saggio]
Capra, Alessandro; M. A., Tini
abstract

Rileivo GPS cinematico per la generazione di un DTM dell'Isola di Nelson (Egitto)

2001 - VLNDEF project: geodetic contribution to geodynamics study of Victoria Land, Antarctica [Capitolo/Saggio]
Capra, Alessandro; Gandolfi, S; Mancini, Francesco; Sarti, S; Vittuari, L.
abstract

NA

2000 - Il telerilevamento per la conoscenza e la pianificazione del territorio urbanizzato [Articolo su rivista]
Capra, Alessandro; Mancini, Francesco
abstract

Sulle applicazioni delle emergenti tecniche di telerilevamento satellitare all'urbanistica.

2000 - Rilievo e rappresentazione di siti archeologici: l'isola di Nelson (Alessandria, Egitto) [Relazione in Atti di Convegno]
Capra, Alessandro; Mancini, Francesco; Tini, M. A.
abstract

Rilievo e rappresentazione di siti archeologici: l'isola di Nelson (Alessandria, Egitto)

2000 - Surface topography of Dome Concordia (Antarctica) from kinematic interferential GPS and bedrock topography [Articolo su rivista]
Capra, Alessandro; R., Cefalo; S., Gandolfi; G., Manzoni; I. E., Tabacco; L., Vittuari
abstract

Determination of surface topograpghy of Dome C area, Anatrtica. Generation of the DTM of the area with GPS kinematic method: data and results analysis.

1999 - Comparison between photogrammetrical surveys of the S.Stefano churches cloister in Bologna and metrics evaluation of the operation of restoration [Articolo su rivista]
Capra, Alessandro; S., Gandolfi; G., Lombaridni; A., Zanutta
abstract

Comparison between photogrammetrical surveys of the S.Stefano churches cloister in Bologna and metrics evaluation of the operation of restoration

1999 - Kinematic GPS for the study of tidal undulation of floating ice tongue [Articolo su rivista]
Capra, Alessandro; S., Gandolfi; C., Lusetti; C., Stocchino; L., Vittuari
abstract

Several experimental tests on the use of kinematic GPS to measure ice shleves undulation under the effects of sea tidal. Comparison sea tidal pressor sensor observations

1999 - Verso il monitoraggio ambientale dell’Antartide su scala globale. Il progetto VECTRA [Relazione in Atti di Convegno]
Capra, Alessandro; Coren, F; Frezzotti, M; Mancini, Francesco; Sterzai, P; Vidmar, R.
abstract

Verso il monitoraggio ambientale dell’Antartide su scala globale. Il progetto VECTRA.

1998 - Comparison between glacier ice velocities inferred from GPS and sequential satellite images [Articolo su rivista]
M., Frezzotti; Capra, Alessandro; L., Vittuari
abstract

Determination of a methodolgy of GPS and remote sensing techniques integration for the determination of glacier ice veloicity in Antartcica

1998 - Comparison between TEC values derived from antarctic GPS measurements and atmospheric soundings [Articolo su rivista]
Al Bayari, O; Capra, Alessandro; Mancini, Francesco; Vittuari, L.
abstract

Ionospheric refraction introduces a delaying effect on GPS observables (code and carrier phase measurements) and therefore on the precise relative position derived. This cannot be completely solved by GPS dual frequency techniques that only take into account the geometric effect of the ionosphere (first order approximation; Ciraolo, 1994) considered as an undisturbed region associated with a constant vertical gradient of Total Electron Content TEC (Menge, 1996). Non-geometric effects also play a fundamental role in signal-ionosphere interactions mainly in equatorial and auroral regions (such as Antarctica) where the severe ionospheric conditions influence the GPS signals (scintillation phenomena). In an attempt to understand and model this effect, we computed the TEC values from selected 1993 GPS Antarctic dataset, using different GPS-based methods. Finally we compared the GPS-derived TEC values with those computed with the ionospheric model based on atmospheric soundings, performed simultaneously to the GPS measurements and in the same region (Terra Nova Bay, Antarctica) by a researcher from the Istituto Nazionale di Geofisica (Rome). The TEC values from GPS observables and atmospheric soundings showed good agreement, taking into account the extreme variability of the phenomenon investigated and the strong dependence on satellite orbital parameters (elevation and azimuth).

1998 - Geodetic network in a global reference frame [Articolo su rivista]
Capra, Alessandro
abstract

Description of geodetic research made in Antarctica as a contribution for a global geodetic reference frame definition.

1998 - GPS for ice sheets movement monitoring and grounding line detection [Capitolo/Saggio]
Capra, Alessandro; Frezzotti, M; Mancini, Francesco; Radicioni, F; Vittuari, L.
abstract

Use of static and kinematic GPS for the determination of ice sheets movement and for the gounding line detection.

1998 - Italian Geodetic network as reference frame for geodynamics purposes (Terra Nova Bay- Victoria Land-Antarctica) [Capitolo/Saggio]
Capra, Alessandro; Radicioni, F.; Vittuari, L.
abstract

geodetic network established and surveyed by italian researchers with the purposse of reference frame establòioshment and for geodynamic studies in northern Victoria Land.

1997 - Italian geodetic researches in Antarctica and International Collaboration [Articolo su rivista]
Capra, Alessandro
abstract

Italian geodetic researches in Antarctica and International Collaboration

1996 - Actual and simulated results in GPS networks [Capitolo/Saggio]
Al Bayari, O.; Capra, Alessandro; Unguendoli, M.; Vittuari, L.
abstract

The apper shows the analysisi of data obtained form different GPS networks in order to simulate an optimized configuration and data acquisition.

1996 - ANTARTIDE vivere nel continente bianco. Su rivista Espande [Altro]
Capra, A.
abstract

1996 - Experiments on the repeatability of the geodetic continous kinematic GPS survey of rails, roads and cableways [Altro]
Capra, A.; Manzoni, G.
abstract

1996 - GPS network for the deformation control in the Mount Melbourne area (Antarctica) : preliminary results of third measurements campaign [Capitolo/Saggio]
O., Al Bayari; Capra, Alessandro; F., Radicioni; L., Vittuari
abstract

GPS network for the deformation control of a volcano located close to italian base in Antarctica.Results analysisi and interpretation.

1996 - Italian Geodetic activities in Antarctica [Capitolo/Saggio]
Capra, A.; Gubellini, A.; Radicioni, F.; Vittuari, L.
abstract

1996 - Kinematic GPS Profiles and Navigation in Antarctica [Articolo su rivista]
Capra, Alessandro; F., Radicioni; L., Vittuari
abstract

Applications of Kinematic GPS for navigation and positioning purpose in antarctica for glaciers monitoring. The application is made under severe conditions like those in antarctica.

1996 - Rilievo fotogrammetrico subacqueo del Palazzo a mare di Tiberio (Isola di Capri -Napoli) [Mostra]
Capra, A
abstract

1995 - Fotografia selezionata e pubblicata [Esposizione]
Capra, A
abstract

1995 - GPS geodetic activities in the 1994-95 antarctic campaign [Working paper]
Capra, A; Radicioni, F
abstract

1995 - Reti GPS per il controllo di deformazioni: analisi dei risultati ottenuti con differenti programmi di elaborazione dati [Articolo su rivista]
Capra, Alessandro; A., Gubellini; L., Vittuari
abstract

Reti topografiche rilevate con sistemi GPS per il controllo delle deformazioni superficiali della crosta terrestre.

1994 - Application of underwater photogrammetry for the deformation control of submerged objects [Articolo su rivista]
Capra, Alessandro
abstract

Underwater low cost photogrammetric systems application to the deformation control of submersed structures.

1994 - Applicazione di sistemi non convenzionali per la fotogrammetria terrestre: rilievo fotogrammetrico della Villa Rustica di felino(Parma) [Capitolo/Saggio]
Capra, A.; Catarsi, M.; Magro, S.
abstract

1994 - Applicazioni non navigazionali del posizionamento dinamico in tempo reale. [Articolo su rivista]
Bitelli, G.; Capra, Alessandro; Unguendoli, M.; Vittuari, L.
abstract

Test sperimentali su sistemi GPS per posizionamenti dinamici con obiettivi di elevata precisione.

1994 - La fotogrammetria subacquea per il rilievo di grotte sommerse [Capitolo/Saggio]
Capra, A
abstract

1994 - On the use of static GPS measurements to record the tidal response of a small antarctic ice shelf (hells Gate ice shelf-Victoria Land) [Articolo su rivista]
A., Bondesan; Capra, Alessandro; A., Gubellini; J. L., Tison
abstract

Recent developments of GPS (Global Positioning System) technology provide a new powerful tool to study ice shelfocean dynamical interactions. Here we present results from feasibility tests on the use of static GPS measurements to locate grounding zones and study their impact on the ice shelf mechanical response. The Hells Gate Ice Shelf has been chosen as a study case owing to its vicinity from Terra Nova Bay Station and to the peculiar problems it raises to glaciologists and geophysicists. Technical and analytical problems are discussed and 5 short time lapse records, in various places at the ice shelf surface, are interpreted. Most of the survey stations appear to react fully hydrostatically to the tidal forcing, even during a secondary maximum of only a few centimeters amplitude. The most upstream station 4, located in a strait between Vegetation Island and the Northern Foothills, shows departure from hydrostatic equilibrium in accordance with a scheme of bedrock valley sides effects. The GPS curve recorded suggests that the ice shelf might not always behave elastically in grounding zones as also testified by periods of intense microseismic actiity into the ice shelf during part of the day.

1993 - Alcune prove sperimentali per la verifica della precisione di sistemi fotogrammetrici non convenzionali. [Articolo su rivista]
Baratin, L.; Capra, A.; Dithiene, C.; Folloni, G.; Guerra, F.; Lombardini, G.; Russo, P.; Stumpo, D.; Travisan, C.; Vittuari, L.
abstract

1992 - Analisi della ripetibilità del metodo GPS differenziale [Articolo su rivista]
Capra, Alessandro; R., Cefalo; G., Manzoni; A., Patrono
abstract

Esperimenti di GPS cinematico su autoveicoli , su imbarcazioni a motore e veicoli ferroviari, cabine di funivie. Risultati degli esperimenti ai fini della determinazione della ripetibilità e per determinare le traiettorie.

1992 - Applicazioni del metodo GPS differenziale [Articolo su rivista]
G., Bitelli; Capra, Alessandro
abstract

Test sperimentali di funzionamento del sistema GPS in modalità differenziale con misure di codice.

1992 - Non-Conventional System in Underwater Photogrammetry [Articolo su rivista]
Capra, Alessandro
abstract

Experimental test of non conventional low cost systems on underwater photogrammetry. The results are presented in terms of potentiality either on final accuracy.

1992 - Pseudo-metric analytical photogrammetric system: comparisons and controls [Articolo su rivista]
L., Baratin; Capra, Alessandro; C., Dithiene; G., Folloni; F., Guerra; G., Lombardini; P., Russo; D., Stumpo; C., Trevisan; L., Vittuari
abstract

Pseudo-metric analytical photogrammetric system: comparisons and controls

1991 - Establishment of a GPS network in the Tyrrennian basin [Capitolo/Saggio]
Achilli, V; Capra, A.; Et, Al
abstract

1991 - Subsidence control in the town of Bologna [Relazione in Atti di Convegno]
Capra, Alessandro; G., Folloni; P., Russo
abstract

Subsidence control in the town of Bologna

1991 - Test di controllo e taratura per i teodoliti integrati:risultati di prove sperimentali condotte sul teodolite elettronico integrato Zeiss mod. Elta3 [Articolo su rivista]
Capra, Alessandro; Russo, Pasquale; A., Selvini
abstract

Descrizione dei test per la verifica di funzionamento e la taratura di teodoliti integrati applicando le norme ISO_DIN per misure di angoli e distanze.

1991 - The GPS application for the study of subsidence in the territory of Bologna [Capitolo/Saggio]
Bitelli, G.; Capra, A.; Folloni, G.; Gubellini, A.; Marsella, M.; Postpischl, D.; Radicioni, F.; Russo, P.; Vittuari, L.
abstract

1990 - Programma di rilievo per il controllo di scorrimenti visco-plastici del terreno [Capitolo/Saggio]
Bitelli, G.; Capra, A.; Folloni, G.; Gubellini, A.; Marsella, M.; Postpischil, D.; Russo, P.; Stumpo, D.; Vittuari, L.
abstract

1990 - Rilievi su binari ferroviari con il GPS in movimento [Articolo su rivista]
Manzoni, G.; Capra, A.; Crisman, B.; Vattovani, D.
abstract

1989 - Bathymetric and seismic reflection survey of a landslide lake [Capitolo/Saggio]
Capra, A.; Gasperini, L.; Gasperini, M.; Postpischil, D.
abstract

1989 - Bathymetric and seismic reflection survey of a landslide lake [Articolo su rivista]
Capra, Alessandro; L., Gasperini; M., Gasperini; D., Postpischil
abstract

Recurring large scale landslides have regularly damned the natural flow of water in the high basin of the Savena river, causing large flooded areas; the most recent of these flooded areas is the Castel dell'Alpi lake ( Bologna) which formed in 1952. Bathymetric and seismic reflection profiles wre made in order to evaluate the filling rate of the lake. This note describes the measurements techniques and the results obtained. The study showed that the lake will be filled i about 40 years.

1989 - Primi risultati relativi allo studio sperimentale di un teodolite elettronico integrato Zeiss modello Elta 3 [Capitolo/Saggio]
Capra, A.; Russo, P.; Selvini, A.
abstract

1988 - A levelling network for the geometrical control of the ground subsidence and its effects in the town of Bologna [Capitolo/Saggio]
Capra, A.; Folloni, G.; Russo, P.; Tomassini, L.
abstract