Short-range ground moving target indication in forward looking airborne radar based on elevation prefiltering

Clutter suppression for short-range ground moving target indication in forward looking airborne radar is a challenging problem because of the range-dependent clutter. If the pulse repetition frequency is chosen so high that radar clutter is range ambiguous, then additional blind velocities at short-range induced by far-range clutter will occur. To eliminate these additional blind velocities, an efficient beamspace-based adaptive prefiltering method in elevation is proposed in this study to suppress ambiguous far-range clutter. The proposed beamformer can provide nearly optimal adapted elevation pattern because of the improved training data selection strategy. After eliminating the impact of ambiguous far-range clutter, the Doppler-compensation-based space-time adaptive processing method could be carried out to suppress residual range-dependent short-range clutter. In addition, the proposed prefiltering method is computationally efficient, and hence it is suitable for engineering application.