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Margarit G.,Defense Systems | Mallorqui J.J.,Polytechnic University of Catalonia | Pipia L.,Polytechnic University of Catalonia | Pipia L.,Institute Cartografic Of Catalonia
IEEE Transactions on Geoscience and Remote Sensing | Year: 2010

This paper studies the polarimetric-dispersion properties of urban targets and their evolution along time in terms of the geometrical configuration. The relations between target geometry and the scattering behavior have been defined through the analysis of large stacks of simulated images. Scattering maps and synthetic aperture radar (SAR) images have been synthesized with the numerical tool GRaphical Electromagnetic COmputing SAR for different qualitative models of two real buildings. Ground-based SAR (GB-SAR) data acquired in a subsidence measurement campaign has been used to assess the simulator's realism. These data have permitted the identification of the critical simulation parameters and their range of recommended values for realistic simulations. In the context of very high resolution images, the results derived from this study may be crucial for making progress in urban-image postprocessing. As the different resolution cells comprise few scattering centers showing a quasideterministic scattering behavior, nonprobabilistic models based on target's geometry seem more suited for scattering modeling. In these models, the geometry-scattering (GS) links precisely inferred from simulated images can be very important. In addition to change detection and land classification, GS models may help in improving the interpretation of subsidence results with differential interferometry. Certainly, new processing algorithms can be developed exploiting the available scattering data with more physical sense. In addition, they can take more advantage of the fine resolution and polarimetric capabilities of the new sensors, like TerraSAR-X or RADARSAT-2. © 2009 IEEE.


Tomas R.,University of Alicante | Romero R.,Indra | Mulas J.,University of Alicante | Mulas J.,Instituto Geologico Y Minero Of Espana | And 14 more authors.
Environmental Earth Sciences | Year: 2014

Subsidence related to multiple natural and human-induced processes affects an increasing number of areas worldwide. Although this phenomenon may involve surface deformation with 3D displacement components, negative vertical movement, either progressive or episodic, tends to dominate. Over the last decades, differential SAR interferometry (DInSAR) has become a very useful remote sensing tool for accurately measuring the spatial and temporal evolution of surface displacements over broad areas. This work discusses the main advantages and limitations of addressing active subsidence phenomena by means of DInSAR techniques from an end-user point of view. Special attention is paid to the spatial and temporal resolution, the precision of the measurements, and the usefulness of the data. The presented analysis is focused on DInSAR results exploitation of various ground subsidence phenomena (groundwater withdrawal, soil compaction, mining subsidence, evaporite dissolution subsidence, and volcanic deformation) with different displacement patterns in a selection of subsidence areas in Spain. Finally, a cost comparative study is performed for the different techniques applied. © 2013 Springer-Verlag Berlin Heidelberg.


Pipia L.,Institute Cartografic Of Catalonia | Fabregas X.,Polytechnic University of Catalonia | Aguasca A.,Polytechnic University of Catalonia | Lopez-Martinez C.,Polytechnic University of Catalonia
IEEE Transactions on Geoscience and Remote Sensing | Year: 2013

Revisiting time constitutes a key constraint for continuous monitoring activities based on space-and airborne synthetic aperture radar (SAR) acquisitions. Conversely, the employment of terrestrial platforms overcomes this limitation and makes it possible to perform time-continuous observations of small space-scale phenomena. New research lines of SAR dealing with the backscattering evolution of different types of scenarios become hence possible through the analysis of ground-based SAR (gbSAR) data collections. The Remote Sensing Laboratory of the Universitat Politècnica de Catalunya drove a one-year measurements campaign in the village of Sallent, northeastern Spain, using its X-Band gbSAR sensor. The field experiment aimed at studying the subsidence phenomenon induced by the salt mining activity carried out in this area during the past decades. In this paper, the polarimetric behavior of an urban environment is investigated at different time scales. After a brief description of the test site and the measurement campaign, the analysis is focused on the stability on man-made structures at different time scales. PolSAR data monthly acquired from June 2006 to July 2007 are employed to stress the presence of nonstationary backscattering processes within the urban scene and the effect they have on differential phase information. Then, a filtering procedure aiming at reducing backscattering randomness in one-day and long-term data collections is then put forward. The improvements provided by the proposed technique are assessed using a new polarimetric descriptor, the time entropy. In the end, the importance of preserving the interferometric phase information from nonstationary backscattering contaminations using fully polarimetric data is discussed. © 2012 IEEE.


Sanchez N.,University of Salamanca | Piles M.,Polytechnic University of Catalonia | Martinez-Fernandez J.,University of Salamanca | Vall-Llossera M.,Polytechnic University of Catalonia | And 5 more authors.
Photogrammetric Engineering and Remote Sensing | Year: 2014

The results of an experiment conducted in Spain over the Soil Moisture Measurement Stations Network of the University of Salamanca (REMEDHUS) are presented. The observations included airborne observations from hyperspectral optical, thermal, and microwave sensors coinciding with intensive field measurements. The hyperspectral optical and thermal datasets were first analyzed and processed to select the best hyperspectral features to be included in the soil moisture retrieval procedure. A linear model linking the selected hyperspectral features to the microwave observations and the in situ soil moisture is proposed. The application of this model resulted in soil moisture estimates that agree with in situ measurements (correlation coefficient: R >0.76, root mean squared differences: RMSD <0.07 m3m-3). The hyperspectral dataset strengthened the link between optical, thermal and microwave L-band observations with soil moisture, and provided a spatial framework to disaggregate soil moisture at very high spatial resolution (3.5 m), useful in hydrological modeling and precision agriculture. © 2014 American Society for Photogrammetry and Remote Sensing.


Ferrer P.J.,Polytechnic University of Catalonia | Lopez-Martinez C.,Polytechnic University of Catalonia | Aguasca A.,Polytechnic University of Catalonia | Pipia L.,Institute Cartografic Of Catalonia | And 3 more authors.
IEEE Geoscience and Remote Sensing Letters | Year: 2011

The use of a low-profile, lightweight, and easy-to-fabricate transpolarizing surface placed on one side of a trihedral corner reflector (TCR) as a polarimetric calibrator is presented in this letter. The transpolarizing TCR presents a high backscattered cross-polar response contrary to standard TCRs. The performance of this device has been tested at the X-band using the Universitat Politecnica de Catalunya ground-based synthetic aperture radar. © 2011 IEEE.


Lopez-Martinez C.,Polytechnic University of Catalonia | Fabregas X.,Polytechnic University of Catalonia | Pipia L.,Institute Cartografic Of Catalonia
ISPRS Journal of Photogrammetry and Remote Sensing | Year: 2011

This paper addresses the problem of speckle noise on single baseline polarimetric SAR interferometry (Pol-InSAR) on the basis of the multiplicative-additive speckle noise model. Considering this speckle noise model, a novel filtering technique is defined and studied in terms of simulated and experimental Pol-InSAR data. As demonstrated, the use of the multiplicative-additive speckle noise model does not lead to a corruption of the useful information but to an improvement of its estimation. The performance of the algorithm is analyzed in terms of the physical parameters retrieved from the filtered data, that in this work correspond to the forest height and the ground phase. In case of experimental data, the retrieved forest height is compared and validated against Lidar ground truth measurements. © 2011 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).


Frontera T.,Institute Geologic Of Catalonia | Concha A.,Institute Geologic Of Catalonia | Blanco P.,Institute Cartografic Of Catalonia | Echeverria A.,University of Barcelona | And 5 more authors.
Solid Earth | Year: 2012

The coseismic superficial deformation at the region of Lorca (Murcia, southeastern Spain) due to the Mw 5.1 earthquake on 11 May 2011 was characterized by a multidisciplinary team, integrating information from DInSAR, GPS and numerical modelling techniques. Despite the moderate magnitude of the event, quantitative information was obtained from the interferometric study of a pair of TerraSAR-X images. The DinSAR results defined the trace of the fault plane and evidenced uplift of the hanging wall block in agreement with the estimated deformation obtained through an elastic rupture dislocation numerical model. Meanwhile for the footwall block, interferometric results showed that tectonic deformation is masked by an important subsidence related to groundwater extraction previously identified at the area of study. Horizontal crustal deformation rates and velocity vectors, obtained from GPS stations existent at the area, were also coherent with the tectonic setting of the southern margin of the Iberian Peninsula and with the focal mechanism calculated for the Lorca event. The analysis of a continuous GPS site in Lorca showed good agreement with the horizontal N-S direction component relative to the numerical model and tectonics of the region. This is the first time at this seismic active area that a multitechnique analysis has been performed immediately after the occurrence of a seismic event, comparing the existing deformation data with a theoretical numerical model based on estimated seismic rupture dislocation. © Author(s) 2012.


Roset R.,Institute Cartografic Of Catalonia | Reoyo-Tudo S.,Universitaries Of Catalonia | Torre-Marin R.,Doc6. Consultores en Recursos de Informacion
Profesional de la Informacion | Year: 2012

Management of digital objects-pictures or other kinds of digital files-is a major challenge for organizations. It is a strategic process that involves several tasks within the institution, from the digitization of a physical document to the right document management process, through proper definition of the functional requirements for the tool used to publish and manage digital objects. A case of two institutions, Consortium of Academic Libraries of Catalonia and the Cartography Institute of Catalonia, is presented. Both faced this strategic process and choose the ContentDm tool for publishing and managing their digital images.


Montaner C.,Institute Cartografic Of Catalonia | Urteaga L.,University of Barcelona
Imago Mundi | Year: 2012

During the Spanish Civil War (1936-1939), the Italian government gave firm cartographic support to the forces of General Francisco Franco. In the first phase, they undertook to engrave and print in Italy a significant collection of military map surgently needed by the Francoistarmy. Later, fromMay1937, the Italian High Command sent to Spain a cartographic unit, the Sezione Topocartografica, that eventually printed more than half a million maps at several different scales. The Italians effectively redesigned the Mapatopográficode Españ at the1:50000scale and selectively edited its topographical content to obtain the road map at the 1:200 000 scale. © 2012 Imago Mundi Ltd.


Pla M.,Institute Cartografic Of Catalonia | Lleopart A.,Institute Cartografic Of Catalonia
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2010

Since 1985 the ICC has been creating and updating topographic and thematic databases and deriving cartographic products using automatic symbolization and semi-automatic generalization. After describing the workflows used to update the ICC databases and the derived products, the paper describes the main aspects of ongoing projects for optimizing updating processes such as extending the data models for supporting incremental updating and versioning, the mechanisms for conveying updated data to the users, and the web based harvesting of information. In addition, the paper describes the prototype developed together with the Harbour Authority of Barcelona and the City of Barcelona for the collaborative updating of topographic data at large scale, and the project of updating the Street database that will be developed together with the municipalities.

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