dc.contributor.author | Foote, Kenneth G. | |
dc.date.accessioned | 2012-09-10T15:08:08Z | |
dc.date.available | 2012-09-10T15:08:08Z | |
dc.date.issued | 1994 | |
dc.identifier.citation | This report is not to be cited without prior reference to the author | no_NO |
dc.identifier.uri | http://hdl.handle.net/11250/105255 | |
dc.description.abstract | Acoustic abundance estimation of dense, vertically extended
aggregations of fish requires knowledge of the extinction cross section.
An established method based on a comparison of the area backscattering
coefficients of fish and underlying flat bottom is exercised for herring
in Ofotfjorden, January 1994, as observed with the SIMRAD EK500/38 kHz
scientific echo sounder and Bergen Echo Integrator. Variability in the
measurement results both for the present period and with respect to earlier
years is viewed in the light of the optical literature. This suggests
that the extinction cross section of finite but complicated physical
scatterers may be as sensitive to details of orientation as is the
backscattering cross section. The possibility of exploiting this property
is considered. | no_NO |
dc.language.iso | eng | no_NO |
dc.publisher | ICES | no_NO |
dc.relation.ispartofseries | ICES CM Documents;1994/(B+D+G+H):2 | |
dc.subject | herring | no_NO |
dc.subject | sild | no_NO |
dc.subject | acoustics | no_NO |
dc.subject | akustikk | no_NO |
dc.subject | stock assessment | no_NO |
dc.subject | bestandsberegning | no_NO |
dc.title | Extinction cross section of herring: New measurements and speculation | no_NO |
dc.type | Working paper | no_NO |
dc.subject.nsi | VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 | no_NO |
dc.subject.nsi | VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452 | no_NO |
dc.subject.nsi | VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 | no_NO |
dc.source.pagenumber | 10 s. | no_NO |