Approach for Range-Ambiguous Clutter Suppression in an AEW Radar System

For an airborne early warning (AEW) radar, when the radar system implements the long-distance moving target surveillance and tracking tasks, the range ambiguity may easily occur due to the limited pulse repetition interval (PRI), which will significantly degrade the target output signal-to-clutter and noise ratio (SCNR) and thus decrease the target detection probability. In addition, the current clutter superimposed by ambiguous clutter components located in different regions will deteriorate the clutter stability, further worsening the multi-channel clutter cancellation performance since the independent identically distributed (IID) property of the clutter training samples has been destroyed. To deal with this issue, the range ambiguity clutter suppression in an AEW radar is considered in this paper. In the proposed algorithm, the multi-channel radar echo signal model with respect to the range-ambiguous clutter is established, and the ambiguous clutter influence is analyzed. Then, the azimuth phase coding (APC) technique is applied to separate the range-ambiguous clutter components in the Doppler domain, which codes every transmitted radar pulse via the appropriate waveform designment. The simulation processing results has been provided to confirm the effectiveness and feasible of the range-ambiguous clutter separation ability.