Determining direction of a noise source in water with four-sensor vector sound intensity arrays of arbitrary geometry

Vector sound intensity (i.e., sound-power flow per unit area) can be used to determine the direction of a sound source in water. A typical vector sound intensity array is composed of three pairs of sensors with pairs aligned along orthogonal axes. Such a typical vector sound intensity array, in our opinion, is still not convenient for engineering implementation. In this paper the four-sensor vector sound intensity array of arbitrary geometry which has less sensors and more flexible configuration than the typical six-sensor array is proposed. First we investigate the direction estimation algorithm based on the four-sensor array. Then we analyze theoretically the error in direction estimation caused by instrument systematic errors and ambient noise. Last, experiments on direction estimation with a four-sensor array were conducted in a semi-anechoic chamber. The theoretical analysis and experiment results all show that the four-sensor array with arbitrary geometry can be used to determine the direction of noise sources.