Ground moving target-detection and focusing imaging under strong noise background

摘要

This study proposes a detection algorithm for a three-channel SAR system with weak ground moving target (GMT)detection and focusing imaging under strong noise background. First, the authors use DPCA cancellation technology to eliminate ground clutter signals. By accumulating the DPCA signal amplitude in the azimuth direction and setting a suitable threshold, they realise GMT detection under strong noise background. After extracting the target range cell DPCA signal, they use the interference processing method to estimate the real-azimuth position of GMT. Then, they perform fractional Fourier transform processing on the extracted DPCA signal. Through the two-dimensional search of the peak point on the (alpha, u) plane of the parameter, the Doppler parameters and velocity estimation of the GMT are obtained. Finally, the azimuth-matching filter is modified to achieve focusing imaging. Simulation results show that the detection probability of GMT is >95% when SNR >= - 27 dB. When SNR = - 27 dB, the authors can achieve fairly accurate parameter estimation of GMT and ideal focusing imaging.