Time filter

Source Type

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

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. Source

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

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. Source

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

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. Source

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

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. Source

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

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). Source

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