Blar i ICES CM documents authored by IMR scientists (1949-2011) på forfatter "Foote, Kenneth G."

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    • Abundance estimation of herring hibernating in a fjord 

      Foote, Kenneth G. (ICES CM Documents;1993/D:45, Working paper, 1993)
      A series of acoustic surveys of the adult component of the Norwegian spring-spawning herring was conducted in Ofotfjorden and Tysfjorden in December 1992. Preliminary results are reported. These include compensation for ...

    • Abundance estimation of Norwegian spring spawning herring wintering in the Vestfjord system, December 1996 

      Ostrowski, Marek; Foote, Kenneth G.; Røttingen, Ingolf; Slotte, Aril (ICES CM Documents;1997/FF:13, Working paper, 1997)
      The spawning stock of Norwegian spawning herring has been surveyed when wintering in the Vestfjord, Tysfjord, and Ofotfjord, in northem Norway in December 1996. The basic method is that of echo integration, with compensation ...

    • Abundance estimation of pelagic fish stocks by acoustic surveying 

      Foote, Kenneth G. (ICES CM Documents;1991/B:33, Working paper, 1991)
      The echo integration technique is outlined. Weaknesses are identified and remedies described. While the technique is adequate for surveying some stocks, improvements are necessary for its proper application to others. ...

    • Acoustic abundance estimation of the stock of Norwegian spring spawning herring, winter 1995- 1996 

      Foote, Kenneth G.; Ostrowski, Marek; Røttingen, Ingolf; Engås, Arill; Hansen, Kaare A.; Hauge, Kjellrun Hiis; Skeide, Roar L.; Slotte, Aril; Torgersen, Øyvind (ICES CM Documents;1996/H:33, Working paper, 1996)
      Standard echo integration methodology has been applied to the stock of Norwegian spring spawning herring (Clupea harengus) wintering in the Ofotfjord-Tysfjord-Vestfjord system during late autumn 1995 and early winter ...

    • Acoustic abundance estimation of wintering Norwegian spring spawning herring, with emphasis on methodological aspects 

      Røttingen, Ingolf; Foote, Kenneth G.; Huse, Ingvar; Ona, Egil (ICES CM Documents;1994/(B+D+G+H):1, Working paper, 1994)
      The spawning component and part of the juvenile stock of Norwegian spring spawning herring have been wintering in a fjord system in northern Norway in recent years. Conditions for measuring the stock size have been ...

    • Acoustic assessment of Norwegian spring spawning herring in the wintering area, December 1995 and January 1995 

      Foote, Kenneth G.; Røttingen, Ingolf (ICES CM Documents;1995/H:9, Working paper, 1995)
      The abundance of the mature component of the stock of Norwegian spring spawning herring has been estimated based on a series of echo integration surveys. These were performed in the wintering area of Ofotfjord, Tysfjord, and ...

    • Acoustic investigation of fish behaviour apropos avoidance reaction 

      Foote, Kenneth G. (ICES CM Documents;1981/B:21, Working paper, 1981)

    • Acoustic portrait of herring in Vestfjord, january 1996, with geostatistical analysis 

      Foote, Kenneth G.; Ostrowski, Marek (ICES CM Documents;1996/H:31, Working paper, 1996)
      In January 1996 the stock of Norwegian spring-spawning herring (Clupea harengus) was acoustically surveyed in the wintering area. Both immature and mature fish were present. Because of the comparative lateness of the ...

    • Acoustic sampling volume for cod 

      Foote, Kenneth G. (ICES CM Documents;1989/B:5, Working paper, 1989)
      This is expressed through the effective equivalent beam angle * for cod as represented by measurements of the tilt angle dependence of target strength. The functional form of * is approximated for each of several behaviour ...

    • Acoustic sampling volume versus equivalent beam angle 

      Foote, Kenneth G. (ICES CM Documents;1988/B:5, Working paper, 1988)
      Irnprovements in target strength measurement have shown the equivalent beam angle (EBA) to be a worrisome source of error in echo integrator surveys. The reason is that the EBA is generally defined as a purely physical ...

    • Angular distribution of overwintering Norwegian spring spawning herring 

      Huse, Ingvar; Foote, Kenneth G.; Ona, Egil; Røttingen, Ingolf (ICES CM documents, Working paper, 1994)
      When plankton production drops off in the fall, adult Norwegian spring spawning herring migrate to two fiords in northern Norway with stable water masses with low temperature and predation. In the wintering areas, the ...

    • Assigning values of target strength and equivalent beam angle in acoustic surveys of fish 

      Foote, Kenneth G. (ICES CM Documents;1991/B:34, Working paper, 1991)
      Contrary to popular opinion, the equivalent beam angle (~) is not determined solely by the transducer directivity. Rather, like the target strength TS, it also depends on the scattering properties of the target fish, but ...

    • Bad-weather calibration of split-beam echo sounder systems 

      Foote, Kenneth G. (ICES CM Documents;1990/B:22, Working paper, 1990)
      A condition for standard-target calibration is stability of the sonar platform and target rig. This condition cannot always be met, nor need it be when the transducer has a split-beam function. Since the position of ...

    • Bathymetric conformal variography of the spawning stock of Northern blue whiting 

      Foote, Kenneth G.; Ostrowski, Marek (ICES CM Documents;1996/S:46, Working paper, 1996)
      Bathymetric-based conformal isotropic and anisotropic variograms are defined. These are applied to the spawning stock of northern blue whiting (Micromesistius poutassou) along the slope of the continental shelf west of the ...

    • Calibration reflector 

      Foote, Kenneth G. (ICES CM Documents;1989/B:4, Working paper, 1989)
      Calibration of scientific echo sounders and integrators entails, inter alia, measurement of the dynamic range. This can be done by repeating on-axis measurements of echoes from each of two different standard targets. ...

    • Coincidence echo statistics 

      Foote, Kenneth G. (ICES CM Documents;1994/B:40, Working paper, 1994)
      Two scatterers at similar range give an echo which may appear to be due to a single scatterer. Methods for determining target strength that depend on resolving single scatterers may fail in this instance. Statistics associated ...

    • Comparison of equal-area cylindrical and circular piston transducers 

      Foote, Kenneth G. (ICES CM Documents;1994/L:29, Working paper, 1994)
      Design of sondes for in situ measurement of zooplankton or other scatterers requires choosing among alternative transducer geometries. This contribution addresses the problem of choosing between cylindrical and circular ...

    • Comparison of two 120-kHz split-beam transducers 

      Foote, Kenneth G. (ICES CM Documents;1991/B:31, Working paper, 1991)
      The performance of two 120-kHz split-beam transducers is compared through the following measures: relative power level, directivity index, relative source level, and reverberation index or equivalent beam angle. Sidelobe ...

    • Cylindrical sonar design for fish echo surveying 

      Foote, Kenneth G. (ICES CM Documents;1988/B:3, Working paper, 1988)
      Most applications of echo integration involve use of a fixed single-beam transducer that is rather narrow and downwards-oriented. It is often desired to sense fish in other directions, for example, to assess components ...

    • Definition of the problem of estimating fish abundance over an area from acoustic line-transect measurements of density 

      Foote, Kenneth G.; Stefánsson, Gunnar (ICES CM Documents;1990/D:25, Working paper, 1990)
      The problem of acoustic abundance estimation is briefly reviewed. Under proper conditions, fish density can be measured with high accuracy along line transects. Observed variations in fish density consequently reflect ...