Modified Adaptive 2-D Calibration Algorithm for Airborne Multichannel SAR-GMTI

The performance of multichannel synthetic aperture radar (SAR)-based ground moving target indication (GMTI) is inevitably restricted by channel imperfections and imbalances, and channel calibration procedure is incorporated into the scheme accordingly. The adaptive 2-D calibration (A2DC) algorithm is sensitive to outliers and suffers from correction errors. To solve the problem, a modified A2DC (MA2DC) algorithm is proposed in this letter. By improving the Doppler calibration model, the proposed MA2DC is more robust than the A2DC algorithm. It can effectively suppress clutter while maintaining detailed features of moving targets, after which the detection capability of moving targets in SAR-GMTI is improved. Its performance is demonstrated by the Gotcha data, which is publicly released by Air Force Research Laboratory.