Passive direction-of-arrival and range estimation for near-field sources

An algorithm for simultaneously estimating the range and bearing of multiple near-field sources is presented. The method is based on the application of signal subspace ideas to the spatial Wigner-Ville distribution approach originally presented by B.R. Breed and T.E. Posch (Proc. ICASSP´84, p.41B.9.1, 1984). The principal advantages of using signal-subspace methods are that the range/direction-of-arrival estimates are obtained with improved precision and resolution, and without computation or search of a complicated spectral surface. Additionally, these methods allow a simple and more effective extension of the spatial Wigner-Ville approach to cases in which noise and/or multiple signals are present. Simulations have shown that the algorithm performs well for a wide variety of test cases, and comparisons with the Cramer-Rao bound indicate near-optimal direction-of-arrival estimates