Clutter suppression algorithm for non‐side looking airborne radar with high pulse repetition frequency based on elevation–compensation–prefiltering

Clutter suppression for non‐side‐looking airborne radar operating at high pulse repetition frequency is an intractable problem because the clutter statistical properties vary with the range, especially in the near range. In addition, the near‐range clutter is always coupled with the far‐range clutter. Elevation prefiltering is recognised as an effective method to suppress the range‐dependent near‐range clutter, but the elevation training samples required must be independent and identically distributed (IID) and not contaminated by the far‐range clutter. Here, an elevation–compensation–prefiltering space–time adaptive processing (STAP) algorithm is developed. In the proposed algorithm, the elevation training samples are selected from the elevation snapshots corresponding to the first pulse, which are not contaminated by the far‐range clutter. An elevation compensation method is presented to alleviate the range dependence, and then there are adequate IID training samples to estimate the elevation covariance matrix. The performance of the near‐range clutter suppression is improved. As for the residual range‐independent far‐range clutter, it can be suppressed by the cascaded azimuth–Doppler STAP. Numerical examples demonstrate the effectiveness of the proposed algorithm.