|Title||Iterative range estimation in a sloping-bottom shallow-water waveguide using the generalized array invariant|
|Publication Type||Journal Article|
|Year of Publication||2017|
|Authors||Cho C, Song H.C, Hursky P., Jesus S.M|
|Journal||The Journal of the Acoustical Society of America|
|Keywords||acoustic arrays,acoustic receivers,acoustic signal processing,acoustic waveguides,underwater sound|
The array invariant theory was generalized by incorporating the waveguide invariant β, referred to as the generalized array invariant. In this paper, the generalized array invariant is extended to mildly range-dependent environments with a sloping bottom where the waveguide invariant is variable in range. Assuming knowledge of the bottom slope, the array invariant can be applied iteratively to estimate the source range starting with β = 1 (i.e., range-independent), which converges toward the correct source range by updating β at the previously estimated range. The iterative array invariant approach is demonstrated using a short-aperture vertical array (2.8-m) in a sloping-bottom shallow-water waveguide from the Random Array of Drifting Acoustic Receivers 2007 experiment, where a high-frequency source (2–3.5 kHz) close to the surface (6-m) was towed between 0.5 and 5 km in range with the water depth varying from 80 to 50 m.