期刊
ICES JOURNAL OF MARINE SCIENCE
卷 67, 期 2, 页码 365-378出版社
OXFORD UNIV PRESS
DOI: 10.1093/icesjms/fsp262
关键词
acoustic scattering; broadband; echosounder; fish; resonance
资金
- US Office of Naval [N00014-04-1-0440, N00014-04-1-0475]
- NOAA/CICOR [NA17RJ1223,]
- NOAA/National Marine Fisheries Service
- WHOI Academic Programs Office
A commercial acoustic system, originally designed for seafloor applications, has been adapted for studying fish with swimbladders. The towed system contains broadband acoustic channels collectively spanning the frequency range 1.7-100 kHz, with some gaps. Using a pulse-compression technique, the range resolution of the echoes is similar to 20 and 3 cm in the lower and upper ranges of the frequencies, respectively, allowing high-resolution imaging of patches and resolving fish near the seafloor. Measuring the swimbladder resonance at the lower frequencies eliminates major ambiguities normally associated with the interpretation of fish echo data: (i) the resonance frequency can be used to estimate the volume of the swimbladder (inferring the size of fish), and (ii) signals at the lower frequencies do not depend strongly on the orientation of the fish. At-sea studies of Atlantic herring demonstrate the potential for routine measurements of fish size and density, with significant improvements in accuracy over traditional high-frequency narrowband echosounders. The system also detected patches of scatterers, presumably zooplankton, at the higher frequencies. New techniques for quantitative use of broadband systems are presented, including broadband calibration and relating target strength and volume-scattering strength to quantities associated with broadband signal processing.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据