EXPLOITING COHERENT MULTIPATH FOR MAINBEAM JAMMER SUPPRESSION

A technique is proposed for the mitigation of jammers that are spatial ly colocated with targets of interest. Spatial nulling methods are ine ffective for these jammers since they cancel the target signal in thei r attempt to mitigate the interference. The traditional approach to th is problem is to integrate for long time periods to boost the signal p ower and 'burn-through' the mainbeam jammer. However, the long time pe riods necessary to acquire a single target in this manner occupy a lar ge amount of the available radar resources and drastically reduce the number of targets the system is able to track. The proposed method exp loits coherent terrain-reflected jammer multipath energy incident on t he radar from other angles to suppress the mainbeam jammer signal. The coherence arises from the fact that the reflected signals are produce d by the same source, i.e. the jammer, as the direct-path signal. By e xploiting this coherence, the proposed method is able to achieve parti al jammer suppression, while maintaining gain on the target, resulting in a reduction in burn-through time requirements.