Calibration of polarimetric SAR images affected by Faraday rotation through the PS technique

The paper proposes a calibration technique based on Permanent Scatterers (PS) for the full-pol L-band and future P-band spaceborne SAR systems. It will be shown how both a radiometric and polarimetric monitoring of the system parameters can be carried out by exploiting the stable targets in the scene. The procedure aims to estimate the overrall system gain, the channel imbalances, and the Faraday rotation angles which must be accounted at such frequencies. The performance achievable by the technique is investigated with concern to the number of images and PSs which shall be supplied to the algorithm in order to meet the desired accuracy requirements.