Robust adaptive ground moving target indication technique applied to distributed spaceborne SAR system

Through formation flying, distributed SAR satellites system can increase the number of spatial degree-of-freedoms (DOFs) and provide flexible multi-baselines for SAR-GMTI(ground moving target indication), while improving the system performance. This letter proposes a robust optimum adaptive clutter suppression technique for SAR-GMTI applied to the distributed spaceborne synthetic aperture radar (SAR) systems. Some realistic problems related to the implementation of the processor are investigated, which include decorrelations from multiplicative speckle noise and moving target steering vector mismatch. Diagonal Loading (DL) techniques is resorted to improve the estimation of clutter statistics in the presence of multiplicative speckle noise. A prior information, like road network information, is integrated into the optimum adaptive processor to reduce moving target steering vector mismatch. Simulation experiments and performance analysis demonstrate the effectiveness and robustness of the proposed processor.