Three-step ground moving target detection method for bistatic forward-looking SAR

Detecting ground moving target in bistatic forward-looking synthetic aperture radar (BFSAR) has become increasingly important in military and civil field. Compared with pulse Doppler radar, the long observation time and high resolution of BFSAR will lead to three problems in the received signal: Doppler ambiguity, large range cell migration and Doppler cell migration, which tremendously aggravate the difficulty of ground moving target detection (GMTD). In this study, the authors propose a three-step ground moving target detection method for BFSAR to solve these problems and achieve good performance on GMTD. First, the bulk-deramp filtering and Keystone transform are exploited to suppress Doppler ambiguity and correct range cell migration, respectively. Then, time-division space–time adaptive processing is utilised for clutter suppression, which eliminates the effect of the Doppler cell migration. Finally, modified Wigner–Ville distribution method is applied to further improve the signal to clutter and noise ratio and the moving target can be detected in the integration domain. Simulations are carried out to demonstrate the effectiveness of the proposed method.