A polynomial rooting approach to the localization of coherently scattered sources

The problem of passive localization of coherently scattered sources with an array of sensors is considered. The spatial extent of such a source is typically characterized by an angular mean and an angular spreading parameter. The maximum likelihood (ML) estimator for this problem requires a complicated search of dimension equal to twice the number of sources. However, a previously reported sub-optimal MUSIC type method reduces the search dimension to two (independently of the number of sources). In this paper, the search over the angular mean parameter in the above MUSIC type technique is replaced by a possibly more efficient polynomial rooting procedure. Computer simulations verify the effectiveness of the proposed method compared to the performance of the ML and MUSIC estimators as well as to the Cramer-Rao bound.