On uniqueness of direction of arrival estimates using RAnk Reduction Estimator (RARE)

We study the uniqueness of the signal Direction Of Arrival (DOA) estimates obtained using the RAnk Reduction Estimator (RARE) [I] in partly calibrated subarray-based sensor arrays. A new identifiability condition is derived for such class of arrays which guarantees that the array manifold is unambiguous. The equivalence of the MUSIC solution for the signal DOA´s (obtained in the fully calibrated array case) and the RARE solution (obtained in the case of partly calibrated array of the same configuration) is proved and the uniqueness of the RARE DOA estimates is established.