An improved omni-directional azimuth angle measurement algorithm of VHF radar

Attributing to the small array aperture of azimuth omni-directional VHF radar, the mutual coupling between antennas can not be neglected so that extra measurement error may be produced. To resolve this problem, an improved unambiguous algorithm is proposed. By simultaneously taking use of mode -1, mode 0 and mode 1 excited by phase mode in angle measurement, the proposed algorithm can eliminate the effect of mutual coupling and acquire the unambiguous value of the azimuth angle. Theoretical analyses and experimental results all demonstrate the effectiveness of the proposed algorithm.