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International Journal of Navigation and Observation
Volume 2008 (2008), Article ID 310656, 16 pages
Review Article

Multichannel Along-Track Interferometric SAR Systems: Moving Targets Detection and Velocity Estimation

Dipartimento per le Tecnologie, Università di Napoli “Parthenope”, Centro Direzionale di Napoli, Isola C4, 80143 Napoli, Italy

Received 19 February 2008; Revised 31 July 2008; Accepted 25 September 2008

Academic Editor: Simon Watts

Copyright © 2008 Alessandra Budillon et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Along-track interferometric synthetic aperture radar (AT-InSAR) systems are used to estimate the radial velocity of targets moving on the ground, starting from the interferometric phases, obtained by the combinations of two complex SAR images acquired by two antennas spatially separated along the platform moving direction. Since the radial velocity estimation obtained from a single-phase interferogram (single-channel) suffers from ambiguities, multichannel AT-InSAR systems using more than one interferogram can be used. In this paper, we first analyze the moving target detection problem, evaluating the systems performance in terms of probability of detection and probability of false alarm obtained with different values of target radial velocity, signal-to-clutter ratio, and clutter-to-thermal noise ratio. Then, we analyze the radial velocity estimation accuracy in terms of Cramer-Rao lower bounds and of mean square error values, obtained by using a maximum likelihood estimation technique. We consider the cases of single-baseline and dual-baseline satellite systems, and we evaluate the detection and estimation performance improvement obtained in the dual-baseline case with respect to the single-baseline one. Sensitivity of the presented method with respect to the involved target and system parameters is also discussed.