An adaptive monopulse processor for angle estimation in a mainbeam jamming and coherent interference scenario

Mainbeam jamming poses a particularly difficult challenge for conventional monopulse radars. In such cases spatially adaptive processing provides some interference suppression when the target and jammer are not exactly co-aligned, but the resulting array pattern is too distorted to be suitable for monopulse processing. The presence of coherent multipath in the form of terrain scattered interference (TSI) is normally considered a nuisance source of interference. However, it can also be exploited to suppress mainbeam jamming with space-time processing. Here we present a method for incorporating space-time processing into monopulse processing to yield a space-time monopulse processor with distortionless spatial array patterns that can achieve far better mainbeam jamming cancellation and target angle estimation than has been previously possible. Performance results for the monopulse processor are obtained for Mountaintop data containing a jammer and TSI, that demonstrate a dramatic improvement in performance over conventional monopulse and spatially adaptive monopulse