Source localization in range-dependent and time-varying shallow water: The Shallow Water 2006 experimental results

In a range-dependent and time-varying environment, such as at the Shallow Water 2006 (SW06) experimental site, matched field processing often has difficulty localizing a moving source emitting a narrowband signal when signal mismatch is difficult to mitigate given only the nominal sound speed profile and bottom properties along the source track. Based on the range-averaged mode wavenumbers and depth functions estimated from data received on a vertical line array by synthetic beamforming (without any environmental information) using Doppler shift as a reference, a method is proposed in this paper to search for the source depth first and then the source range. Source localization is demonstrated with the SW06 data for two source runs along and oblique to the shelf. Robustness is achieved by minimizing/breaking the coupling between range and depth, when one of them can be estimated using non-environment-related input.