Experimental demonstration of passive acoustic tracking using a library of nearby sources of opportunity

Abstract

Acoustic sources can be tracked in the marine environment using a method that is similar to traditional matched field processing but differs in that it uses a library of data-derived replicas in place of modeled replicas. In order to account for differing source spectra between library and target vessels, cross-correlation functions are compared instead of comparing acoustic signals directly. Measured replicas are extrapolated to fully populate a search grid using waveguide invariant theory. The method has been demonstrated experimentally for localizing surface contacts in a shallow water (150 m) environment. Further, we present experimental validation of the method in deeper water and discuss the extension of the technique to sub-surface contacts