ROBUST MAXIMUM-LIKELIHOOD SOURCE LOCALIZATION IN AN UNCERTAIN SHALLOW-WATER WAVE-GUIDE

This paper addresses the problem of matched-field source localization in the presence of uncertainties in the ocean environment. Because sig nal wavefront mismatch can cause anomalous source location estimates, development of robust localization methods is critically important. In this paper, a robust maximum-likelihood estimator is proposed. It is based on a decomposition of the field into predictable and unpredictab le subspaces of the acoustic normal mode representation. The estimator uses the predictable subspace for source localization. Identification of the predictable modes is made according to the second-order joint statistics of the horizontal wave-numbers. The performance of the meth od is evaluated and compared to other matched-field methods using simu lations and acoustic array data from the Mediterranean Sea. In the pre sence of mismatches, the algorithm has superior probability of correct localization than the maximum-likelihood, matched-mode-processing, an d Bartlett methods. (C) 1997 Acoustical Society of America.