Space-time resampling method for the range-dependence of clutter spectrum in non-sidelooking STAP radars

The clutter Doppler frequency depends on range in non-sidelooking arrays for Ground Moving Target Indication, which would lead to an inaccurate estimate of the covariance matrix of the clutter at the range bin of interest in space-time adaptive processing (STAP). According to clutter model, we propose a space-time resampling method which can mitigate the range dependence of clutter spectrums by adjusting the space-time sampling rate. Different from other compensation methods, the method uses an interpolation filter to obtain identical clutter spectrum in both the mainlobe and the sidelobes. STAP is then applied to the output of the filter. The method has low computational complexity. Simulation results show the validity of the proposed method.