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.-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.