Localization of soniferous fish using a sparse hydrophone array and conventional steered response power method

Abstract

A sparse seven-channel hydrophone array was deployed in intertidal marsh creeks located within the North-Inlet-Winyah-Bay Nature Reserve at Baruch Marine Field Laboratory in Hobcaw Barony, Georgetown, South Carolina, USA. for the purpose of localizing the sounds produced by local fish and invertebrates. A conventional approach to localize sound sources was used, consisting of a delay-and-sum beamforming algorithm known as steered response power (SRP) applied to the seven-channel array data during post-processing. This was accomplished by delaying the signal recorded by each channel and combining the signals to “listen” to sounds propagating through the array from candidate source locations. The power of the combined signal was maximized, yielding a likely location for the source position. Two-dimensional localization of the soniferous fishes is possible, with a reasonable degree of robustness to noise and aliasing effects of spatial under-sampling. Accuracy is limited due to field measurements and the number of sound producers in the area.