Browsing Brage IMR by Author "Korneliussen, Rolf"

Now showing items 1-12 of 12

    • CRIMAC cruise report: Development of acoustic and optic methods for underwater target calssification - G.O. Sars 22.11 - 03.12 2022 

      Handegard, Nils Olav; Tenningen, Maria; Bildøy, Leif; Corneliussen, Jon Even; Esmail, Kameran; Heinsdorf, Jens; Khodabandeloo, Babak; Korneliussen, Rolf; Kubilius, Rokas; Kvalvik, Liz Beate Kolstad; Osborg, Eirik Svoren; Pala, Ahmed; Pedersen, Geir; Rosen, Shale; Saltskår, Jostein; Schuster, Erik; Ulset, Ingrid; Westergerling, Eugenie Heliana Taraneh (Toktrapport;2023 - 3, Research report, 2023)
      The overarching objective of the survey is to collect data to support the CRIMAC activities and to collect data for the LoVe observatory. CRIMAC is a center of research-based innovation funded by the research council of ...

    • A deep scattering layer under the North Pole pack ice 

      Snoeijs-Leijonmalm, Pauline; Gjøsæter, Harald; Ingvaldsen, Randi Brunvær; Knutsen, Tor; Korneliussen, Rolf; Ona, Egil; Skjoldal, Hein Rune; Stranne, Christian; Mayer, Larry; Jakobsson, Martin; Gårdfeldt, Katarina (Peer reviewed; Journal article, 2021)
      The 3.3 million km2 marine ecosystem around the North Pole, defined as the Central Arctic Ocean (CAO), is a blind spot on the map of the world’s fish stocks. The CAO essentially comprises the permanently ice-covered deep ...

    • Evaluation of echosounder data preparation strategies for modern machine learning models 

      Ordonez, Alba; Utseth, Ingrid; Brautaset, Olav; Korneliussen, Rolf; Handegard, Nils Olav (Peer reviewed; Journal article, 2022)
      Fish stock assessment and management requires accurate estimates of fish abundance, which are typically derived from echosounder observations using acoustic target classification (ATC). Skilled operators are regularly ...

    • Feasibility study on the use of scientific multibeam sonar to characterize the Atlantic Bluefin Tuna spawning stock 

      Tenningen, Maria; Pena, Hector; Korneliussen, Rolf; Ona, Egil; Pons, Vicent Puig (Rapport fra havforskningen;2019 - 34, Research report, 2019)
      The Institute of Marine Research (IMR) and the Polytechnic University of Valencia (UPV) were invited by ICCAT Atlantic-Wide Research Program for Bluefin Tuna (GBYP) to carry out a feasibility study on the use of scientific ...

    • Finite-amplitude sound propagation effects in volume backscattering measurements for fish abundance estimation 

      Pedersen, Audun Oppedal; Lunde, Per; Tichy, Frank; Korneliussen, Rolf (Peer reviewed; Journal article, 2022)
      Abstract – Scientific advice for governmental management of marine resources relies on acoustical observation methods. Quantification and identification of fish and plankton species are often achieved using multi-frequency ...

    • Mesopelagic fish gas bladder elongation, as estimated from wideband acoustic backscattering measurements 

      Khodabandeloo, Babak; Ona, Egil; Pedersen, Geir; Korneliussen, Rolf; Melle, Webjørn Raunsgård; Klevjer, Thor Aleksander (Peer reviewed; Journal article, 2022)
      Backscattered acoustic energy from a target varies with frequency and carries information about its material properties, size, shape, and orientation. Gas-bearing organisms are strong reflectors of acoustic energy at the ...

    • Micronekton biomass distribution, improved estimates across four north Atlantic basins 

      Klevjer, Thor A.; Melle, Webjørn Raunsgård; Knutsen, Tor; Strand, Espen; Korneliussen, Rolf; Dupont, Nicolas; Salvanes, Anne Gro Vea; Wiebe, Peter H. (Peer reviewed; Journal article, 2019)
      Distribution of micronekton was investigated during early summer of 2013, using data from a cruise covering the central parts of four north Atlantic basins, the Norwegian Sea (NS), Iceland Sea (ICS), Irminger Sea (IRS), ...

    • Nonlinear crosstalk in broadband multi-channel echosounders 

      Khodabandeloo, Babak; Ona, Egil; Macaulay, Gavin; Korneliussen, Rolf (Peer reviewed; Journal article, 2021)
      Distortion of acoustic wave caused by nonlinear propagation transfers acoustic energy into higher harmonics of the transmitted signal. When operating several broadband echosounders with non-overlapping frequency bands to ...

    • Power budget equations and calibration factors for fish abundance estimation using scientific echo sounders and sonar systems 

      Lunde, Per; Korneliussen, Rolf (Journal article; Peer reviewed, 2016-07-09)
      Acoustic methods used in fish abundance estimation constitute a key part of the analytic assessment that makes the basis for abundance estimation of marine resources. The methods rely on power-budget equations and calibrated ...

    • Quantitative processing of broadband data as implemented in a scientific split-beam echosounder 

      Andersen, Lars Nonboe; Chu, Dezhang; Handegard, Nils Olav; Heimvoll, Harald; Korneliussen, Rolf; Macaulay, Gavin; Ona, Egil; Patel, Ruben; Pedersen, Geir (Peer reviewed; Journal article, 2023)
      The use of quantitative broadband echosounders for biological studies and surveys can offer considerable advantages over narrowband echosounders. These include improved spectral-based target identification and significantly ...

    • Structure and functioning of four North Atlantic ecosystems - A comparative study 

      Melle, Webjørn Raunsgård; Klevjer, Thor A.; Drinkwater, Kenneth F.; Strand, Espen; Naustvoll, Lars Johan; Wiebe, Peter H.; Aksnes, Dag Lorents; Knutsen, Tor; Sundby, Svein; Slotte, Aril; Dupont, Nicolas; Salvanes, Anne Gro Vea; Korneliussen, Rolf; Huse, Geir (Peer reviewed; Journal article, 2020)
      The epi- and mesopelagic ecosystems of four sub-polar ocean basins, the Labrador, Irminger, Iceland and Norwegian seas, were surveyed during two legs from Bergen, Norway, to Nuuk, Greenland, and back to Bergen. The survey ...

    • Survey report for CRIMAC SFI 2023 

      Handegard, Nils Olav; Allken, Vaneeda; Holmin, Arne Johannes; Johnsen, Espen; Korneliussen, Rolf; Pedersen, Geir; Skjefstad, Joakim; Rogge, Rabea Patricia; Samuelsen, Mikal Arntzen; Tenningen, Maria; Sivle, Lise Doksæter (Toktrapport;2024 - 7, Research report, 2024)
      This cruise report describes the objectives, methods, and preliminary results from the tasks carried out at the CRIMAC SFI survey. The survey was conducted on board RV G.O. Sars between November 15th (Tromsø) and November ...