Rochet, Marie-Joëlle and Cadiou, Jean-François and Trenkel, Verena M. (2006) Precision and accuracy of fish length measurements obtained with two visual underwater methods. Fishery Bulletin, 104(1), pp. 1-9.
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During the VITAL cruise in the Bay of Biscay in summer 2002, two devices for measuring the length of swimming fish were tested: 1) a mechanical crown that emitted a pair of parallel laser beams and that was mounted on the main camera and 2) an underwater auto-focus video camera. The precision and accuracy of these devices were compared and the various sources of measurement errors were estimated by repeatedly measuring fixed and mobile objects and live fish. It was found that fish mobility is the main source of error for these devices because they require that the objects to be measured are perpendicular to the field of vision. The best performance was obtained with the laser method where a video-replay of laser spots (projected on fish bodies) carrying real-time size information was used. The auto-focus system performed poorly because of a delay in obtaining focus and because of some technical problems.
|Title:||Precision and accuracy of fish length measurements obtained with two visual underwater methods|
|Journal or Publication Title:||Fishery Bulletin|
|Page Range:||pp. 1-9|
|Issuing Agency:||United States National Marine Fisheries Service|
|Depositing User:||Patti M. Marraro|
|Date Deposited:||03 Aug 2012 18:13|
|Last Modified:||03 Aug 2012 18:13|
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