Adaptive beamforming for low-angle target tracking under multipath interference

Angle of arrival estimation of a low-altitude target over the sea surface is a difficult problem due to the multipath coherent interference from the image target. We present a new monopulse technique utilizing an iterative interference cancellation algorithm based on the array antenna structure to overcome performance degradation. Our algorithm is compared with the maximum likelihood estimator, as well as with the existing algorithm employing the specular reflected error finding function.