dc.contributor.author | Dalen, John | |
dc.contributor.author | Bodholt, Helge | |
dc.date.accessioned | 2012-08-28T13:40:17Z | |
dc.date.available | 2012-08-28T13:40:17Z | |
dc.date.issued | 1991 | |
dc.identifier.citation | This report is not to be cited without prior reference to the authors | no_NO |
dc.identifier.uri | http://hdl.handle.net/11250/104870 | |
dc.description.abstract | A research program was initiated in Norway in 1988 for measuring
the abundance of fish resources at depth from 500 to 1000 metres.
It was decided to develope a deep towed vehicle, to bring
acoustic transducers down to 400 metres depth. The vehicle serves
as a stable and quiet platform for the transducer. The
attenuation due to air bubbles in the upper water layers is
avoided, and the transducer is closer to the fish so that the
resolution of single fish is improved. The vehicle has a weight
of 500 kg and is designed as a streamlined torpedo with
accommodation for the transducer, a depth sensor and
inclinometers. A special feature is that the transducer face is
in direct contact with the waterflow below the vehicle. This
eliminates the need for an acoustic window, and all the well
known problems of air bubbles attached to the inner surface of
the window. This paper describes the concept of the vehicle and
the transducer, and gives test results obtained during surveys
in 1990 and 1991. | no_NO |
dc.language.iso | eng | no_NO |
dc.publisher | ICES | no_NO |
dc.relation.ispartofseries | ICES CM Documents;1991/B:53 | |
dc.subject | gear experiments | no_NO |
dc.subject | redskapsforsøk | no_NO |
dc.subject | stock assessment | no_NO |
dc.subject | bestandsberegning | no_NO |
dc.subject | acoustics | no_NO |
dc.subject | akustikk | no_NO |
dc.title | Deep towed vehicle for fish abundance estimation concept and testing | no_NO |
dc.type | Working paper | no_NO |
dc.subject.nsi | VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fisheries technology: 924 | no_NO |
dc.source.pagenumber | 13 s. | no_NO |