Target strength spectra of tracked individual fish in schools

摘要: Broadband sonar echoes received from individual fish in schools contain information that might be useful for species discrimination. The echo characteristics are closely related to the incident angle of sound body, corresponding apparent tilt a viewpoint transducer. Therefore, it is necessary isolate and estimate angles. In this study, broadband split-beam sounder system was used extract features free-swimming schools. Echoes dense were measured their position estimated using with downward-oriented acoustic beam. Individual tracked Japanese jack mackerel Trachurus japonicus, chub Scomber red sea bream Pagrus major system. target strength (TS) spectra ranging 80 120 kHz calculated sorted on basis angle, which by tracking result. Using approach, TS obtained entire fish, found dependent angles involved.