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, multi-channel 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 respect to the single-baseline one. Sensitivity of the presented method with respect to the involved target and system parameters is also discussed.
Multichannel Along-Track Interferometric SAR Systems: Moving Targets Detection and Velocity Estimation
BUDILLON, Alessandra;PASCAZIO, Vito;SCHIRINZI, Gilda
2008-01-01
Abstract
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, multi-channel 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 respect to the single-baseline one. Sensitivity of the presented method with respect to the involved target and system parameters is also discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.