A Parametric Approach to Extended Source Localization

Abstract: Point source modeling is frequently used in m ay processing. Although this assumption is good for many applications, thm are some situations where point source modeling is unrealistic. For instance, in a multi-beam echo sounder, a reflected signal from the scs floor appears as a spatially extended source. In this paper we investigate distributed sources. The approach is based on the a~sumpti~ that the correlation kernel of the distributed source belongs to a family of parametric functions. We generalize the MUSIC algorithm to distributed signal parameter estimator (DSPE). The DSPE locaZizer minimizes a scdar product between an estimated basis for the noise subspace and the m ay manifold. We study two cases corresponding to completely correlated and totally uncorrelated signal distributions, We also discuss limitations of the application of ordinary beamformer techniques to spatially distributed signals by computing the may gain. It is shown that the array gain is upper bounded by a value which depends on the extension width of the source. Thus increasing the number of the sensors in a beamformer does not necessarily increase the resolution. 1