Acoustic ranging and waveguide invariant parameter estimation using virtual arrays.

Abstract

A method for estimating the range of an unknown broadband acoustic source in a waveguide [Thode et al., J. Acoust. Soc. Am. 108(4), 1582–1594 (2000)] is revisited and extended to estimate both waveguide invariant parameter “beta” and source range in shallow water. In the new method, two or more vertical arrays are used without requiring a signal sample from a guide‐source. It was shown that both methods are mathematically identical and they both provide robust range estimation even when the reference signal sample is used from different time and/or different vertical array location. It was also demonstrated that an image processing tool, Hough Transform method, provides robust parameter estimation from virtual array output data. In addition, the parameter estimation method was validated under both summer and winter conditions by using incoherent noise data to localize and track merchant vessels and to estimate waveguide invariant parameter. [Work supported by the Office of Naval Research.]