Adaptive digital beamforming for preserving monopulse target angle estimation accuracy in jamming

The monopoulse technique for target angle estimation fails when there is sidelobe and/or mainlobe jamming. If not effectively encountered, electronic jamming prevents successful radar target detection and tracking. We have developed a technique which cancels one mainlobe jammer and multiple sidelobe jammers in such a way that enables both target detection and unbiased monopulse angle estimation. Our technique makes use of adaptive digital beamforming for sidelobe jamming cancellation followed by a mainlobe canceller for mainlobe jamming cancellation. A constrained adaptation is imposed to maintain the mainbeam in the sidelobe cancellation process.