Eigenstructure-based ambiguity resolution algorithm for distributed subarray antennas VHF radar

Distributed subarray antennas (DSAs) have been proposed to enhance angular resolution and the accuracy of direction of arrival (DOA) estimation. This results in the well-known grating lobes in the array beampattern or ambiguities in DOA estimation. Presented is a slanting DSA composed of two widely-separated uniform rectangular arrays. By exploiting the translational invariance and the aperture coupling in the DSA configuration, a novel ambiguity resolution algorithm is proposed. It can provide closed-form, low-variance and automatically paired 2D direction cosine estimates. Simulation results are presented to verify the efficacy of the ambiguity resolution algorithm.