Research of the ambiguity restraint in five-element cross-shaped array

The ambiguity problem of direction of arrival (DOA) estimation in uniform cross-shaped array is caused by the large element-spacing. From the viewpoint of matrix, the ambiguity can be described as the complete equality of the steering-vectors generated by the estimated false angle and true angle. In order to break the balance, which the steering-vectors generated by the false and true angle are completely equal, a novel method is proposed, in which an additional element with small spacing to the origin is added in the five-element uniform cross-shaped array. From the results of mathematical analysis and simulation, it is found that the method proposed can revise the steering-vector, restrain the false peak and improve the accuracy of DOA estimation greatly.