基于宽带回声信号ESP的鱼数量评估方法

Fish Abundance Estimation Based on Statistical Property of Broadband Acoustic Echo Energy

针对窄带信号条件下回波能量起伏特性的鱼数量评估方法适用性差的问题,提出了一种鱼群宽带回声信号能量起伏特性的鱼数量评估方法,将鱼群的声散射视作多个处于随机运动状态的个体鱼散射亮点的相干叠加,通过对鱼群宽带回波脉冲压缩输出信号能量的归一化二阶统计量建模,实现鱼数量的评估。仿真结果表明:与窄带回波能量统计特性的鱼数量评估方法相比,提出的方法能适用于更大鱼群密度条件下的鱼群评估,且在相同鱼群条件下,具有更高的评估精度,统计所需样本量更少。预期可以为鱼类资源量评估提供技术支持。

The existing method for fish number density estimation based on narrowband acoustic echo energy of fish school is of poor applicability.Aiming at solving this problem,a method based on statistical property of broad-band acoustic echo energy of fish school was proposed in the paper.In this method,the backscattered sound of fish school is treated as the coherent superposition of the random distributed individual fish.And fish number is calculated using normalized second order statistical property of the plus-compression output signal energy of broadband backscat-tered sound of fish school.The simulation result indicates that the new method is appropriate for denser fish density situation compared with the existing narrowband statistic approach.Furthermore,it is also more precise and less sta-tistic sample needing.This method is expected to provide technical support for fish abundance estimation.