沿海声层析仪的设计与实现

Design and implementation of coastal acoustic tomography

为解决在对沿海海流进行大面积连续观测中受到活跃的渔业活动和繁忙的海上交通的限制,设计研制了一对沿海声层析仪样机.该仪器采用了M序列调制信号,利用GPS时钟进行异地时间同步,完成水下信号的发射和接收,实现双向声传播时间的精确测量.仪器设计工作频率为3~7.5 kHz,异地时间同步精度达0.5μs.实验室调试的接收信号峰值明显,信噪比最大达25.7 dB.

IIn order to make a breakthrough allowing continuous monitoring of current fields in coastal seas without disturbing shipping traffic and fishing activities,the coastal acoustic tomography（CAT） system was developed.The CAT system was designed to transmit and receive sound signals simultaneously,accurately measuring acoustic travel time between separated stations using the M-sequence sound signal and a GPS clock.The operating frequency of the CAT system was set at 3～7.5 kHz,and the accuracy of the clock at 0.5μs.A prominent peak in the signal-to-noise ratio was obtained during lab tests,with the maximum signal-to-noise ratio reaching 25.7 dB.