The relative frequency response, as derived from individually separated targets on cod, saithe and Norway pout ...

• Main Authors: Pedersen, Geir, Korneliussen, Rolf J., Ona, Egil
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: ASC 2004 - R - Theme session 2024
• Subjects: Fisheries and aquaculture; Technologies and data; atlantic cod; Gadus morhua
• Online Access: https://dx.doi.org/10.17895/ices.pub.25349737; https://ices-library.figshare.com/articles/conference_contribution/The_relative_frequency_response_as_derived_from_individually_separated_targets_on_cod_saithe_and_Norway_pout/25349737

No abstracts are to be cited without prior reference to the author.The relative frequency response is an important acoustic feature used to characterise acoustic targets. This response has been defined as the sv, volume backscattering coefficient, for a specific frequency relative to that of a reference frequency (38 kHz). The acoustic data commonly used in these calculations are derived from integrated measurements in a region containing multiple targets. In this study the relative frequency responses at 18, 38, 70, 120, and 200 kHz have additionally been measured using filtered target strength data on all frequencies. The spatial comparability of the sv-data is thus avoided, while the single-target detection becomes a new challenge. Target strength was extracted from in situ measurements, using calibrated and digitised data from a Simrad EK60 with split-beam transducers transmitting simultaneously at all five frequencies. Selected series with nearly pure catches of Atlantic cod (Gadus Morhua L.), saithe ...