Second-order near-field source localization: algorithm and performance analysis

A new method for the estimation of the DOA and range parameters of near-field sources is introduced. The proposed method proceeds in two steps and uses only the second-order statistics of the observations collected from a uniform linear array. The first step is a signal pre-processing which consists in the computation of some properly chosen spatial correlation sequences of the observed signal. This correlation coefficients are shown to be time series harmonic sequences and their harmonic frequencies are nonlinear functions of DOAs and ranges of the source signals. The second step consists in the estimation of the harmonic components using a weighted least square criterion in terms of the linear prediction polynomial of the correlation sequence. The source azimuths and ranges are then calculated from the estimated harmonic components. Performance analysis and optimal weighting matrix are derived in terms of the source parameters and the array output second order statistics. The effectiveness of the proposed method is illustrated by some numerical simulations.