Passive ocean acoustic tomography using ships as sources of opportunity recorded on an irregularly spaced free-floating array: A feasibility study

Abstract

This presentation investigates the practical feasibility of using an adaptive volumetric array, such as a series of free-floating buoys with suspended hydrophones, which record ships as acoustic sources of opportunity in coastal waters for performing acoustic thermometry or other environmental inversions in near-shore environments in a totally passive manner. Ships are tracked using the Automatic Identification System (AIS). Numerical simulations using a standard normal mode propagation model were first used to test limitations of the proposed approach with respect to frequency band, drifting receiver configuration, signal to noise ratio, precision, and accuracy of the inversion results, along with sensitivity to environmental and position mismatch. Performance predictions using this model are compared with experimental results using at-sea data collected off the coast of New London, CT, in Long Island Sound during August of 2015.