Direction of Arrival (DOA) Estimation using Vector Acoustic Data

Monitoring the acoustic and particle motion generated during construction of offshore wind farms is important to understanding the impact of construction activities on the marine environment. Particle motion is important for some fishes and invertebrates since they sense and respond to it. Acoustic pressure and particle velocity measurements were made during the construction of Coastal Virginia Offshore Wind Farm (CVOW) off the Virginia coast in 2020. The CVOW wind farm consisted of two wind turbines and one of them implemented mitigation measures during construction. The pressure and particle motion produced by the pile driving activities during construction were measured using a tetrahedral array of hydrophones and four Ocean Bottom Recorders (OBX). The 3-dimensional particle motion and acoustic pressure data measured during the pile driving events were utilized to set up direction of arrival (DOA) estimation algorithms in this study. The sensor packages were properly oriented using the known location of one of the wind turbines. Based on this orientation the DOA from the second turbine was calculated and compared with its known location.