THE RESOLUTION THRESHOLD OF A DIRECTION-FINDING ALGORITHM FOR DIVERSELY POLARIZED ARRAYS

Subspace-based algorithms for narrowband direction-of-arrival (DOA) estimation require detailed knowledge of the array response (the array manifold) and assume that the noise covariance matrix is known up to a scaling factor. In practice, these quantities are not known precisely. Resolution and estimation accuracy can degrade significantly when the array response or the noise covariance deviate from their nominal values. In this work, we examine the resolution threshold of a recently proposed subspace-based algorithm for direction finding with diversely polarized arrays. We study finite sample effects, and the effects of modeling errors (errors in the array manifold or the noise covariance), on the resolution threshold. A comparison is made between the resolution thresholds of the MUSIC algorithm (for uniformly polarized arrays) and the proposed algorithm (for diversely polarized arrays).