说明：  Firstly, this study does research on the quantitative uation of the acoustic performance of the planar ultrasonic array sensors. Sparse signal decomposition theory is then applied to find three different directions of arrival (DOAs) of the signal the PD source to the array sensor. Next, using two of the DOAs (azimuth and pitch), the location of the PD is determined as the centre of a sphere whose surface is tangential to the three DOAs in three different planes. The positioning accuracy of the sensors is then derived. Finally, simulation results show that the acoustic performance of the circular array is the best. It also produces the most accurate location results. Therefore, a circular array is the optimal form to use for the construction of a planar array sensor.