A Space-time Adaptive Processing Method Based on Deramp Processing

In multichannel Synthetic Aperture Radar-Ground Moving Targets Indication (SAR-GMTI) systems, three problems are led by utilizing the conventional Post Doppler-Space-Time Adaptive Processing (PD-STAP) technique. Firstly, the target Doppler spectrum is wrapped because of the Doppler shift caused by the cross-track velocity of the moving target. The ambiguities are appeared if directly using the matched filtering. Secondly, in the case of the signal undersampling, a Pulse Repeating Frequency (PRF) shifting is caused in the azimuth direction for a moving target in the focused image. This makes the moving target detection much more complicated and challenging. Thirdly, the traditional PD-STAP technique also has a high computational complexity. To overcome these problems, a novel space-time adaptive processing method based on Deramp processing is proposed. Simulation results validate the effectiveness of the proposed algorithm.