Assimilation of Distributed Targets and PS Information for the Monitoring of Polarimetric SAR Systems

The paper presents a novel technique for the polarimetric monitoring of spaceborne SAR systems based entirely the available in-scene information. The key role is played by the stable targets, namely polarimetric Permanent Scatterers, which are detected through multi-image processing. The exploitation of temporal information in addition to the spatial statistics used for Distributed Targets, allows for a temporal differential monitoring of every distortion parameter of the system (overall gain, imbalances and cross-talks) even without the presence of a calibrated reflector. The technique has been tested on a Radarsat-2 Fine Quad-pol stack of 26 images over the Barcelona area reporting an imbalance stability below 0.2 dB and cross-talk estimates within -35 dB.