An Improved Method for 2D DOA Estimation Based On a Vector Sound Intensity Array

Vector sound intensity can be used to locate sound sources. The typical vector sound intensity array is composed of three pairs of sensors with pairs aligned along orthogonal axes. Each sensor pair provides one of the components of the three dimensional intensity vector which is the time average of the product of the pressure and particle velocity at the center of the sensor pair. In the conventional method, the pressure is the arithmetic mean of the pressures measured by a sensor pair. A systemic error in 2D DOA (direction of arrival) estimation which increases with increasing frequency is produced by the pressure approximation. The paper proposed an improved method for improving the accuracy of direction estimation by replacing the arithmetic mean with geometrical mean to calculate the acoustic pressure. Tests were conducted in a semi-anechoic chamber with a 0.2 m typical vector sound intensity array. The numerical and experimental results all proved that the improved method can greatly decrease the error in direction estimation caused by the pressure estimation error