Robust Adaptive Pulse Compression Under Encode-Decoder Network for Synthetic Aperture Radar

Abstract

The matched filter is widely used in traditional synthetic aperture radar system with the criteria of maximum output signal-noise-ratio (SNR). However, matched filter has high-level side lobes (for example, 13. 6dB without windowing) resulting in severe masking for adjacent weak targets. Recently, an adaptive pulse compression (APC) was developed based on minimum mean square error (MMSE) between true ground profiles and compressed outputs. Though has better compression results, it requires tremendous amount of time for processing, which hinders its applications. In this paper, a fast implementation named iterative adaptive pulse compression (IAPC), is designed whereby the respective tap coefficients of all filters are jointly updated with a recursive way and subsequently we incorporate it into the classic range Doppler algorithm via changing the processing sequence, which is shown to be obviously efficient with pulse duration increasing. Moreover, an encoder-decoder architecture is developed for improving the targets’ energy to solve the SNR-dependence of both APC and IAPC. As a result, through various stressing experiments including simulation and real data validation, the proposed method is shown to be superior to the original APC and matched filter in the views of time efficiency and peak sidelobe ratio (PSLR) respectively.