Conditions for the precise measurement of fish target strength in situ.
Conditions for the precise measurement of fish target strength in situ.
复制标题
DOI：
10.3135/jmasj.20.73
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
K. Sawada;M. Furusawa;N. Williamson
中科院分区：
文献类型：
--
作者：
K. Sawada;M. Furusawa;N. Williamson
对原位鱼目标强度（TS）精确测量的条件进行了实证研究，并为此引入了两个指标。一个是在某一时刻有助于形成回声的有效混响体积中的鱼的数量，另一个是从单个回声提取的残差得出的多重回声的百分比。随着这两个指标的下降，测得的目标强度接近某个渐近值，该值在过去的研究中被认为是可靠的。这表明存在一些阈值并且低于这些阈值TS测量将会成功。 1991 年 8 月 15 日至 16 日日本和美国船只进行船间校准时，从白令海东部陆架的一个大型同一鱼群获得的数据集证实了这两个指数的有效性。
Conditions for precise measurement of in situ fish target strength (TS) are empirically studied and two indexes are introduced for this purpose. One is the number of fish in the effective reverberation volume which contributes echo formation at a certain instant and the other is the percentage of the multiple echoes which is derived from a residual of the single echo extraction. With the decrease of both indexes measured target strength approach a certain asymptotic value which is admitted as reliable from the past study. This shows the existence of some threshold values and below these threshold values TS measurement will be successful. The effectiveness of both indexes is confirmed by the data set obtained from one large same fish school in the eastern shelf of Bering sea during the intership calibration between Japanese and U.S. vessels on 15 and 16 August 1991.