Open lake experiment for direction of arrival estimation using acoustic vector sensor array

Acoustic vector sensor measures scalar acoustic pressure along with particle motion in three orthogonal directions and finds wide range of application in underwater acoustics. This study presents the experimental results using a vector sensor array for Direction of Arrival (DOA) of an acoustic signal from a known orientation. Experiment was conducted at a controlled lake environment and based on conventional beamforming technique DOA of the source was calculated. Frequencies ranging from 1 to 6 kHz at 1 kHz interval were used as source for a fixed orientation of the vector sensor array. Later the experiment was repeated by changing the orientation of the array along different azimuthal directions for specific frequencies at a range of 100 m. The results obtained from the beamformer output compares well with the known source direction along the azimuth. Vector sensor array could able to estimate both elevation and azimuth without left right ambiguity and gives better result compared to scalar sensor. The Experimental results from the array raise confidence to use the system in at-sea experiments for passive acoustic monitoring as well as marine mammal localization.