Passive Direction-of- Arrival and Range Estimation for Near-Field Sources'

A6airaciThe majority of model-based techniquen proposed to date for solving the multiple source direction-ofarrival (DOA) estimation problem operate under the assumption that the wavefronts impinging on the array are planar. However, when nourcea are located close to the array (i.e., in the near-field), the inherent curvature of the wavefront is no longer negligible. In this paper, we propose the use of high-resolution signal subspace methods in conjunction with a spatial version of the Wigner-Ville distribution (WVD) to solve the near-fleld problem. Advantages of this approach are that accurate source range/DOA estimates are obtained with relatively good resolution, and without computation or search of a three-dimensional spectral surface. The effectiveness of the algorithm is demonstrated by extensive simulations, and its performance relative to the Cram&-Rao bound is also presented.