Quality of underwater source localization in a multipath environment

Abstract

This paper investigates the accuracy of a passive underwater localization system using two submerged omnidirectional sensors in a multipath environment. Expressions for the variance and bias of localization error are developed for two sources of error: ocean noise and sensor perturbations. Expressions are also given for the variance of time delays obtained from the cross correlation of the two sensor signals. It is shown that the variance of localization error is very sensitive to vertical sensor perturbations. It is also shown that in the region where the time difference of arrival (TDOA) of the surface reflected paths is approximately equal to the TDOA of the direct paths, the localization error is very large.