A Full Field Inversion Method for Acoustic Tomography of Ocean Currents

Abstract

An extension of the matched field inversion technique to include oceanic current tomography is considered. Matching of the non-reciprocity of acoustic fields propagated in opposite directions (instead of matching sound fields themselves) makes it possible to separate relatively subtle acoustic effects of the currents from those due to sound speed variations, bottom topography etc. A set of numerical simulations is carried out under environmental conditions typical of the Gulf Stream to evaluate the stability of the inversions with respect to mismatches in transceiver positions and in sound speed for various choices of physical quantities to be matched. Matching of non-reciprocity in phase is shown to result in sufficient sensitivity to current velocity and high stability with respect to mismatches in other parameters.