El Radar : de dónde viene y hacia dónde va

Peer Reviewe

El Radar : de dónde viene y hacia dónde va

Peer Reviewe

Observacio de la terra amb sensors passius de microones

Peer ReviewedPostprint (published version

CFAR data fusion center with inhomogeneous receivers

Detection systems with distributed sensors and data fusion are increasingly used by surveillance systems. A system formed by N inhomogeneous constant false alarm rate (CFAR) detectors (cell-averaging (CA) and ordered statistic (OS) CFAR detectors) is studied. A recursive formulation of an algorithm that permits a fixed level of false alarms in the data fusion center is presented, to set the optimum individual threshold levels in the CFAR receivers and the optimum `K out of N' decision rule in order to maximize the total probability of detection. The algorithm also considers receivers of different quality or with different communication channel qualities connecting them with the fusion center. This procedure has been applied to several hypothetical networks with distributed CA-CFAR and OS-CFAR receivers and for Rayleigh targets and interference, and it was seen that in general the fusion decision OR rule is not always the bestPeer ReviewedPostprint (published version

Obtención de modelos digitales del terreno y detección de pequeños movimientos de la superficie terrestre mediante interferometría radar desde satélite

La interferometría SAR es una técnica que mediante la combinación coherente de imágenes radar de alta resolución de la superficie terrestre permite obtener patrones de interferencia de fase, los interferogramas, directamente relacionados con la geometría de la escena (el relieve). Un tratamiento posterior que involucra procesos críticos como un desenrollado de fase bidimensional y una georreferenciación considerando las efemérides del satélite y un modelo preciso de la superficie terrestre (datum) permite obtener - con algunas restricciones - un modelo digital del elevaciones del terreno (DEM) con precisiones en altura del orden de 10 m rms. Un segundo grupo de aplicaciones es la medida de pequeños movimientos de la superficie terrestre con una precisión por debajo del centímetro; estas aplicaciones diferenciales son las que han permitido estudiar el efecto de la atmósfera en los interferogramas SAR. En el artículo se muestran resultados obtenidos a partir de imágenes ERS-1 y ERS-2 de Tarragona.Peer ReviewedPostprint (published version

Formación de imágenes radiométricas a frecuencias de microondas. Aplicaciones en teledetección

This paper presents the different contributions to the radiation measured by a radiometer, and how they can be related to the physical features of the scene. Several models have been designed to simulate radiometric observationsover sea and land. Some radiometric images have been obtained showing the brighness temperature of earth surface and its dependence on surface characteristics, moisture, temperature, wind over sea, etc.Peer ReviewedPostprint (published version

Formación de imagenes radiometricas a frecuencias de microondas. Aplicaciones en teledetección

This paper presents the different contributions to the radiation measured by a radiometer, and how they can be related to the physical features of the scene. Several models ha ve been designed to simulate radiometric observationsover sea and land. Sorne radiometric images have been obtained showing the brighness temperature of earth surface and its dependence on surface characteristics, moisture, temperature, wind over sea, etc.Peer ReviewedPostprint (published version

Observació de la terra amb sensors pasius de microones

Peer ReviewedPostprint (published version

Sensitivity equations and calibration requirements on airborne interferometry

The usage of an airborne interferometric SAR to mass map production is strongly dependent on the capability of performing the data processing in a near automatic mode. One of the main limitations is related to both the accurate calibration of the system parameters, its stability from flight to flight and the correct in-flight recording of aircraft position and attitude. The unstable movements of an airborne SAR platform, if recorded in an accurate manner, can be corrected during the processing step. Measurement errors and time drifts lead to location errors in the final DEM. The system requirements in both accuracy and stability to fulfil a quality-mapping requirement can be resolved from the sensitivity equations. The same equations can be also used to calibrate the system parameters from the location errors on the imaging of well-known targets, usually corner reflectors.Peer ReviewedPostprint (published version