An effective method of choosing vertical beam pitch angle of sonar array

Abstract

In order to obtain a better array gain, the sonar main-beam should point to the incident direction of acoustic waves. For stereoscopic sonars, such as cylindrical array sonar, the incident direction of acoustic wave contains both horizontal angle and vertical pitch angle (VPA). Due to the variation of acoustic VPA caused by hydrological condition, the array gain would decrease seriously when the VPA of sonar beam doesn't match the VPA of acoustic waves. To solve the above problem, we proposed a VPA optimization method for stereoscopic sonars. First,we analyzed the variation rule of both sonar array gain and the acoustic VPA. Then,search for the VPA of the sonar beam in the vertical directions by beam scanning, so as to maximize the array gain. Simulations results are provided to validate the performance of the proposed method.