Rotary way to resolve ambiguity for planar array

In this paper we address a novel method of eliminating ambiguity for planar array. It is known that ambiguity appears in the direction of arrivals (DOA) estimation when the aperture of the array is large enough. We propose a method of rotating the array to solve the ambiguity problem. Firstly, we use multiple signal classical algorithm (MUSIC) to estimate DOA. Then we rotate an angle of the array and use MUSIC again to obtain the spatial spectrum. Later, a rotary MUSIC (R-MUSIC) algorithm defined as root of two spectrums product is proposed, which can suppress pseudo peaks of spectrum. Furthermore, an Improved R-MUSIC (IR-MUSIC) is raised to improve the performance. Finally, simulation results for circular array show that the rotary method of resolving ambiguity is feasible and effective. And we also evaluate the suppression performance for different rotation angles.