Estimation of Direction of Arrival of Biological Sound using Acoustic Vector Sensor Array in Shallow Water off Chennai

Abstract

Mahanty, M.M.; Latha, G.; Sridhar, P.S.S.R., and Raguraman, G., 2020. Estimation of direction of arrival of biological sound using acoustic vector sensor array in shallow water off Chennai. In: Sheela Nair, L.; Prakash, T.N.; Padmalal, D., and Kumar Seelam, J. (eds.), Oceanic and Coastal Processes of the Indian Seas. Journal of Coastal Research, Special Issue No. 89, pp. 52-57. Coconut Creek (Florida), ISSN 0749-0208.The primary objective of this study is to estimate the direction of arrival (DOA) of biological sound by using an acoustic vector sensor array, deployed in the shallow waters off Chennai during the period 30th August-14th September, 2016. A vector sensor measures the scalar acoustic pressure along with acoustic particle velocity in three orthogonal directions. Based on the spectrogram analysis, Terapontidae fish chorus is identified in distinctive patterns associated with daily timing and frequency content throughout the recording. The chorus is species-specific with the spectral peak frequency extended over 0.6-1.5 kHz in each day after dusk, and indicates these sound signals are associated with spawning. The single call duration is about 0.35-0.45 s, and comprised of a series of pulses ranging from 35-40. By considering the single call as a sound source from the recorded Terapontidae fish chorus, the DOA is determined based on conventional beamforming technique with respect to dominant frequency of that particular sound source, and estimated both azimuth and elevation using vector sensor array components. The study clearly shows the application of the vector sensor array, and can be useful to estimate source localization of the biological sound and their movement in the marine environment in future work.