Gerard Margarit

GMV · Remote Sensing Application Services

Determining the kinematic state of objects in space is a topic of major concern for both researchers and spacecraft operators. The scientists and engineers are, e.g., interested in the influence of the attitude changes on the orbit of the object, be it for long-term propagations of the state vector or for re-entry predictions, driven by the varying...

This paper presents a comparative study among four operational detectors that work by automatically post-processing synthetic aperture radar (SAR) images acquired from the satellite platforms RADARSAT-2 and COSMO-SkyMed. Challenging maritime scenarios have been chosen to assess the detectors' performance against features such as ambiguities, signif...

This paper presents the results obtained by GMV in the maritime surveillance operational activations conducted in a set of research projects. These activations have been actively supported by users, which feedback has been essential for better understanding their needs and the most urgent requested improvements. Different domains have been evaluate...

Remote Sensing Specialist and Project Manager, Remote Sensing Applications and Services Division (RSAS) Payload Data Processing and Applications (PDPA) GMV Aerospace and Defence, GMV A&D Balmes, 268-270 5 th floor, Barcelona, SPAIN 1. ABSTRACT This paper presents the outcomes of the EC FP7 NEREIDS project focused to move forward to an integrated ma...

In the above paper (ibid., vol. 49, no. 8, pp. 3129-3138, Aug. 2011), the funding information is incorrect. The correct funding information is presented here.

This paper presents the main figures of the FP7 project NEREIDS granted in the Space 2010 call. This project aims to provide a test benchmark for the most popular and recently proposed techniques that are available in the field of maritime surveillance. This covers from target detection to abnormal pattern alarm triggering passing through data fusi...

This paper presents a new ship classification methodology that uses single-pol synthetic aperture radar (SAR) images to categorize targets based on a fuzzy logic (FL) decision rule. As such, the method tries to overcome the lack of an operational solution that is able to reliably classify ships with one SAR channel. The method has the following thr...

This paper presents a synthetic aperture radar (SAR) simulator that is able to generate polarimetric SAR (POLSAR) and polarimetric inverse SAR data of complex targets. It solves the electromagnetic problem via high-frequency approximations, such as physical optics and the physical theory of diffraction, with notable computational efficiency. In pri...

The range of applications where Earth Observation (EO) can be useful has been notably increased due to the maturity reached in the adopted technology and techniques. In most of the cases, EO provides a manner to remotely monitor particular variables and parameters with a more efficient usage of the available resources. Typical examples are environm...

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 h...

This paper presents a Ship Monitoring System (SIMONS) working with Synthetic Aperture Radar (SAR) images. It is able to infer ship detection and classification information, and merge the results with other input channels, such as polls from the Automatic Identification System (AIS). Two main stages can be identified, namely: SAR processing and data...

The necessity to control all the activities within the marine environment is nowadays vital for most official authorities. Besides protecting the ecosystem and providing safety and surveillance along the transportation corridors, illegal immigration and sustainable economic activities are also issues to cover. Since early nineties, a lot of efforts...

This paper presents a new ship monitoring system developed at GMV Aerospace that integrates the reports provided by the Automatic Identification System (AIS) with ship-related information derived from SAR data analysis. In contrast to other proposals, SAR data is considered here to be the main input whereas AIS polls the supporting channel. The sys...

This paper evaluates the potentialities of polarimetric ship scattering for basing classification methods that provide reasonable performance within cluttered scenes. Both simulated and airborne polarimetric synthetic aperture radar (SAR) images have been used to validate the conclusions of a previous phenomenological study. Numerical simulations h...

This paper presents a study on the origin of the dominating scattering mechanisms observed in polarimetric synthetic aperture radar (SAR) images of ships. The study has been made by using numerical simulations, which have been carried out with a radar cross section (RCS) prediction tool (GRaphical Electromagnetic COmputing) and a SAR simulator. Ext...

This paper performs a preliminary study about the potentialities of 3D dispersion maps on developing building characterization. Polarimetric Interferometric SAR images obtained from the SAR simulator GRECOSAR are used to evaluate if buildings can be differentiated by means of a particular 3D distribution of scattering centers accounting the Pauli m...

This paper uses a complete and realistic SAR simulation processing chain, GRECOSAR, to study the potentialities of Polarimetric SAR Interferometry (POLInSAR) in the development of new classification methods for ships. Its high processing efficiency and scenario flexibility have allowed to develop exhaustive scattering studies. The results have reve...

This paper presents a new benchmark for techniques validation based on a multidimensional database of simulated data. By exploiting a SAR simulator of complex targets, series of numerical simulations may be run for specific sets of observation conditions and the results made public. Targets are in principle focused on urban structures, despite any...

This paper is focused to evaluate the influence of sea clutter in the performance of ship classification algorithms based on single-pass Polarimetric SAR Interferometry (PolInSAR). For such purpose, series of numerical simulations have been carried out with GRECOSAR, the SAR simulator of complex targets developed by UPC. There, different types of v...

This paper studies the scattering behavior of urban environments using simulated data generated with GRECOSAR, a SAR simulator of complex targets. Large series of scattering maps have been obtained at C/X band for qualitative models of real buildings. They belong to a neighborhood where RSLab is carrying out a campaign with a Ground-based SAR (GB-S...

The modeling of complex target response in SAR imagery is the main subject of this paper. The analysis of a large database of SAR images with polarimetric and interferometric capabilities is used to accurately establish how the different structural parts of targets interact with the incident signal. This allows to relate the reflectivity informatio...

This paper tackles the most important discretization effects appearing when simulating sea surface around ships. Their impact on model parameters is used to assess which approximations are mandatory for reaching affordable trade-off between simulation loads and data accuracy. This study has been developed with GRECOSAR, a SAR simulator of complex t...

This paper presents a novel method for vessel classification based on single-pass polarimetric synthetic aperture radar (SAR) interferometry. It has been developed according to recent ship scattering studies that show that the polarimetric response of many types of vessels can be described by trihedral- and dihedral-like mechanisms. The adopted met...

This paper performs a preliminary study about the influence of the sea in vessel classification. For such purpose, a novel method based on single-pass polarimetric SAR inter- ferometry has been adopted. This method analyzes the input data with the Pauli theorem and, then, retrieves the height related to the local maxima present in each Pauli channe...

This paper presents a preliminary study about the scattering properties of urban-like scatters based on simulated SAR images. A simple target performed by a box of gypsum located over a perfectly conducting flat plane is analyzed for different views in both ISAR and SAR fully-polarimetric modes. The results are analyzed with the Pauli decomposition...

This paper analyzes the worsening effects the sea surface can induce on vessel classification algorithms working with SAR imagery. Two issues will be tackled, the complex motion history of ships and the polarimetric scattering mechanisms generated by the sea-hull interaction. Both can modify the information that allows to infer the geometry of ship...

This paper presents a vessel classification approach for SAR imagery that combines polarimetry and interferometry. By analyzing the measured data with the Pauli theorem and deriving interferograms for each channel, accurate tri-dimensional representations of ships' geometry are provided. The correlation of this output with a pattern database built...

This manuscript tackles the possible usage of Polarimetric SAR interferometry in vessel classification. It presents a simple technique that combines the retrieved height information with a Pauli analysis of polarimetric data to build a tri-dimensional map of scattering centers. By comparing this output with a vessel pattern database generated from...

First Page of the Article

This paper presents a study performed with high resolution simulated SAR data that outline the limitations of polarimetric coherent decompositions on vessel classification. In these days, these theorems have been set up as the most advisable alternative for this application but an evident lack of real data avoids know their true usefulness. In this...

This paper presents a numerical tool able to generate realistic SAR images from accurate vessel models for a given orbital sensor. Its capability to extract high resolution radar signatures converts this SAR simulator in a useful tool for vessel classification studies and, furthermore, to define a future constellation of SAR sensors bound for carry...

This paper continues the work developed in related to a numerical tool able to simulate the full-polarimetric raw data for a given orbital SAR system from a realistic vessel model. This simulator makes possible the construction of a precise database of vessel radar signatures that will be used to develop classification algorithms. The simulator wil...