Monopulse Angle Estimation With Adaptive Dual Sum‐and‐Difference Beamforming

ABSTRACT

For planar arrays, adaptive sum and difference beamforming (ADBF‐SD) forms ‘canyon‐shaped’ null regions (CSNRs), which cause severe estimation errors and echo attenuation for off‐interference targets in the CSNRs, especially under main lobe interference. A monopulse angle estimation method based on adaptive dual sum‐and‐difference beamforming is proposed for planar monopulse arrays to alleviate the impacts of CSNRs. By setting main lobe constraint points to generate two sum beams with mutually perpendicular CSNRs and their corresponding difference beams, two monopulse ratio surfaces and estimation results are obtained, with the final target angle estimation derived from the fusion of these results. Compared with ADBF‐SD methods, simulation results demonstrate that the proposed method significantly improves the accuracy of target angle estimation