Range ambiguity clutter rejection in spaceborne bistatic radar systems

In a spaceborne bistatic radar system, where the transmitter and receiver are physically distinct, the background clutter usually exhibits severe spatial-temporal two-dimensional range dependence. Then the suppression residues from the range ambiguous clutter components may appear outside the main-lobe clutter region and the additional filtering notches may be formed, ultimately reducing the clean area for moving target detection. This paper presents a method aimed at this problem, which suppresses range ambiguous clutter through inter-pulse random phase coding. This method can effectively alleviate the influence of range ambiguous clutter via signal mismatching along Doppler dimension, and thus enhances the clutter suppression robustness at the expense of a certain reduction in target signal-to-clutter-plus-noise ratio. Simulated results are provided to evaluate the feasibility and performance of this method in different spaceborne radar configuration cases.