Mixing Matrix Calibration for BSS Range Ambiguity Suppression in Multichannel SAR Systems

Abstract

A significant level of range ambiguity disturbance may affect high-resolution wide-swath spaceborne synthetic aperture radar (SAR) systems with multiple elevation receive beams. To overcome this limitation, a promising approach, based on the higher order blind source separation (BSS), was recently proposed. This method, denoted as range ambiguity BSS (RABSS), demonstrates outstanding range ambiguity suppression performance when applied to heterogeneous scenes. Nevertheless, a degradation is expected for relatively homogeneous scenes. In this letter, the RABSS method is extended by introducing a novel mixing matrix calibration procedure. The robustness of the proposed approach towards different types of imaged surfaces is numerically analyzed by means of realistic simulations, which rely on the backscattering coefficients of TerraSAR-X images and the simulated antenna patterns of a large array-fed reflector antenna employing multiple elevation beams.