Doppler Separation-Based Clutter Suppression Method for Passive Radar on Moving Platforms

For passive radar on moving platforms, the clutter suppression performance of the space-time adaptive processing (STAP) is degraded significantly. This article reveals the underlying reason that the high sidelobes of strong clutter raise the noise eigenvalue power level of the space-time covariance matrix. To tackle this problem, we propose a Doppler separation-based clutter suppression method. The proposed method first separates the clutter at different Doppler frequencies, and then performs clutter suppression for each Doppler interval. The Doppler separation operation can mitigate the influence of clutter sidelobes effectively. In clutter Doppler separation, the construction criteria of Doppler extension subspace and time delay extension subspace are also established. Simulated and field experimental results demonstrate the effectiveness of the proposed method in suppressing strong clutter while avoiding significant loss of target signal to interference plus noise ratio (SINR).