中文摘要：

针对离岸深水网箱养殖的鱼群安全问题，提出了一种基于水声多波束技术的鱼群状态监测新方法。该方法采用环形水声多波束阵在深水网箱中进行分区探测，结合多路声信号处理技术、数据无线传输技术和虚拟仪器技术，实现了深水网箱中鱼群状态的远程、实时监测。与传统电机旋转扫描方法比较，该方法结构简单、功耗小，探测速度快，完成一次全网箱探测只需4s；采用回波能量积分算法估计鱼群量，偏差值小于25％。监测仪样机在海上易于安置、操作方便；在福建泉州围头海域深水网箱养殖现场不同的海况条件测试中性能稳定、可靠。

英文摘要：

Aiming at the safe problem of fish shoal in offshore fish cage, a monitoring method based on underwater acoustic multi-beam technique is introduced. The method employs an annular multi-beam array to detect the fish cage in division cage scanning mode, which integrates with the techniques of multi-path signal processing, wireless data communication and virtual instrument, and can implement the remote real-time monitoring of the offshore fish cage. Compared with traditional method of motor rotating cage scanning mode, the method simplifies the system structure, diminishes power dissipation and accelerates scanning speed. It takes only 4s to accomplish an entire cage scanning. By using the algorithm of energy integral, the deviation of the fish amount estimation is less than 25%. The prototype is easy to install and operate. Test results in the pool and in the field of Weitou harbor, Quanzhou of Fujian show that the system has good performance under different environment conditions.