Array Partition Angle Measurement Method for Distributed Array Radars in Mainlobe Jamming

In the modern complex electromagnetic environment, array radar systems usually apply adaptive beamforming techniques to form nulls toward the jamming angles for jamming cancellation. However, for mainlobe jamming, the nulls lead to beam distortion, which degrades the performance of angle measurement dramatically. This paper proposes an angle measurement method based on array partition for distributed array radars in the presence of mainlobe jamming. First, the distributed array is partitioned into a subarray-level large aperture virtual array and an element-level small aperture array. Then the adaptive beamforming is performed for the large virtual array to generate narrow nulls at the jamming direction, while the small aperture array forms monopulse sum and difference beams to measure the target angle. Thus, the proposed method effectively suppresses the mainlobe jamming and measures the target angle accurately. Finally, the correctness and effectiveness of the proposed method are verified by simulation experiments.