童剑锋¹，韩 军^1，2，浅田 昭²，溝口雅彦³
（1 上海海洋大学海洋科学学院，上海 200090；
2 东京大学生产技术研究所，东京153-8505；
3 日本NUS，东京108-0022）

摘要：香鱼的资源量至今主要靠目视计数来掌握，这种方法很耗劳动力且精度低。由华盛顿大学研发的声学摄像仪DIDSON（Dual-frequency IDentification SONar）可在浑浊不清的水中摄取接近光学视频画质的图像。其附带软件虽可对体长为几十厘米的大个体鱼计数，但对于体长6 cm以下的小个体鱼，由于其回波信号弱，计数显得非常困难。本文提供了一种基于DIDSON的溯河洄游幼香鱼计数的新方法。首先从声学图像中消除静止的背景，提取出运动目标并除去噪音像素，然后用卡尔曼滤波器对剩下的目标进行跟踪，根据目标移动的特性把目标分为香鱼和垃圾2大类，在除去向下游移动的垃圾之后，可正确地计算向上游移动香鱼的数量。通过现场实测验证了上述声学计数方法的实用性和高效性。

关键词：幼香鱼；鱼量计数；DIDSON；渔业资源调查

Counting method of upstream juvenile Ayu （Plecoglossus altivelis） by acoustic camera

TONG Jian-Feng1, HAN Jun1,2, ASADA Akira2, MIZOKUCHI Masahiko3
( 1 College of Marine Sciences, Shanghai Ocean University, shanghai200090, China; 2 Institute of Industrial Science, University of Tokyo, Tokyo 153-8505, Japan;3 Japan NUS Co., Ltd, Tokyo 108-0022, Japan )

Abstract: In order to comprehend the abundance of ayu, direct visual counting has been mainly used so far which is not only labor-intensive, but also its counting accuracy is poor. Recently, an acoustic camera called DIDSON (Dual-frequency IDentification SONar), which is invented by Washington University, can provide almost-video-quality images to identify objects even in turbid water. Its software’s fish counting function is useful for counting big fishes which are several dozen centimeters large. As for the small fishes whose length are only 6 centimeters or less, it becomes technically difficult to count them because their echo image are too weak and small. In this paper we present a new method for counting small size juvenile ayu that migrates upriver using a DIDSON. We first subtract the stationary background from the acoustic image and remove noises. Then we track the remained targets by Kalman filter. According to the character of the moving targets, we sort out the targets into two groups--ayu and garbage. After removed the garbage going downstream, we reached the correct counting of the upstream fishes. The above acoustic counting method has been proved to be useful and effective by an experiment.

Keyword: Plecoglossus altivelis; fish-counting; DIDSON; survey of fishery resources

作者简介: 童剑锋（1983—），男，硕士研究生，研究方向：水下信息探测与处理。E-mail: jf.tong@yahoo.com.cn

通讯作者: 韩军（1963—），男，教授，研究方向：水下信息探测与处理。E-mail: jhan@shou.edu.cn

（来源：《渔业现代化》 2009，36（2），29-33）