The changeable sampling-rate processing technology with application to SAR-MTD

The echo of a moving target for airborne Synthetic Aperture Radar (SAR) can be approximated by the chirp signal. The changeable sampling-rate processing technology (CSPT) proposed by us is an effective technique to detect the frequency modulation rate of a chirp signal, but the remaining Doppler frequency diminishes its performance. In this paper, the influence of remaining Doppler frequency on the performance of CSPT is analysed and a new algorithm proposed to eliminate the remaining Doppler frequencies of all chirp components simultaneously based on the signal reconstruction from its ambiguity function. Therefore the improved CSPT can achieve excellent detection performance for the chirp signal. This method is applied to airborne SAR moving target detection (MTD), and the detection scheme is presented. Finally, the improved CSPT is demonstrated by using raw ground clutter data combined with a simulated moving target.