Blar i Brage IMR på forfatter "Hjellvik, Vidar"

Viser treff 21-23 av 23

    • The measurement error of marine survey catches: the bottom trawl case 

      Hjellvik, Vidar; Godø, Olav Rune; Tjøstheim, Dag (ICES CM Documents;2001/P:6, Working paper, 2001)
      We have formulated a model for analyzing the measurement error of marine survey abundance estimates using data from parallel surveys (trawl haul or acoustic measurement). The measurement error is defined as the component ...

    • Tracking individual fish from a moving platform using a split-beam transducer 

      Handegard, Nils Olav; Patel, Ruben; Hjellvik, Vidar (Journal article; Peer reviewed, 2005)
      Tracking of individual fish targets using a split-beam echosounder is a common method for investigating fish behavior. When mounted on a floating platform like a ship or a buoy, the transducer movement often complicates ...

    • Using artificial neural networks to combine acoustic and trawl data in the Barents and North Seas 

      Neville, Suzanna; Hjellvik, Vidar; Mackinson, Steven; Kooij, Jeroen van der (ICES CM documents, Working paper, 2004)
      Groundfish have a wide and variable distribution making the use of trawling alone a highly inadequate sampling method. Trawl data provide species identification and numbers over a very small area and habitat type while ...