Blar i ICES CM documents authored by IMR scientists (1949-2011) på forfatter "Foote, Kenneth G."
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On the frequency dependence of target strength of mature herring
Foote, Kenneth G.; Hansen, Kaare A.; Ona, Egil (ICES CM Documents;1992/B:10, Working paper, 1992)Mature herring (Clupea harengus), hibernating in Ofotfjord in December 1991, was measured simultaneously at each of three frequencies: 18, 38, and 120 kHz. Measurements of the mean volume backscattering coefficient were ... -
Performance of an acoustic sonde design
Foote, Kenneth G. (ICES CM Documents;1994/L:30, Working paper, 1994)The potential of multi-frequency acoustic technology for quantifying fish and plankton is widely recognized. At a U.S. GLOBEC workshop in 1991, one of the considered problems was measuring macrozooplankton and micronekton. ... -
Relation of maximum and average target strengths for the same fish
Foote, Kenneth G. (ICES CM documents, Working paper, 1987)The relation is studied by means of tabulated measurements of the tilt angle dependence of target strength for three gadoid species. The dependence of the difference target strength on fish length is statistically ... -
Scheme for displaying fish position data in real time
Foote, Kenneth G. (ICES CM documents, Working paper, 1987)Fish reaction to the passage of acoustic surveying vessels may be at least partly assessed through use of the angle data derived with the SIMRAD split-beam echo sounder. Several schemes are outlined for displaying and ... -
Simulating echograms
Foote, Kenneth G. (ICES CM Documents;1989/B:6, Working paper, 1989)Simulation of echo data can be useful for verifying echo integrators realized in computer software. A model is presented which associates distinct stochastic processes with each of the following: bottom depth; number, ... -
Simultaneous two-sphere two-transducer calibration
Foote, Kenneth G. (ICES CM Documents;1990/B:23, Working paper, 1990)When directional transducers are mounted nearby, the central lobes of their beam patterns may partly overlap at ranges typical for standard-target suspension in calibration exercises, e.g., 20 m. According to the ... -
Some pitfalls of short-range standard-target calibration
Ona, Egil; Foote, Kenneth G.; Zhao, Xianyong; Svellingen, Ingvald (ICES CM Documents;1996/B:36, Working paper, 1996)Often it is necessary or desirable to perform a standard-target calibration at rather short range, for example, because of shallow water or interest in measuring animals at short range. A number of general range-dependent ... -
Sound speed measeurments of Antarctic krill
Foote, Kenneth G. (ICES CM Documents;1989/B:7, Working paper, 1989)The longitudinal sound speed in Euphausia superba has been measured by time of flight of an acoustic pulse through a suspension of krill in a T-shaped tube with nominal path length of 20 cm. Results are presented. -
Spheres for calibrating an eleven-frequency acoustic measurement system
Foote, Kenneth G. (ICES CM Documents;1989/B:3, Working paper, 1989)Calibration of a single resonant transducer by standard sphere is a simple matter. How does one calibrate an array composed of eleven different resonant transducers spanning the frequency range from 27 to 710 kHz? A ... -
Summary of methods for measuring fish target strength
Foote, Kenneth G. (ICES CM Documents;1988/B:4, Working paper, 1988)Methods for measuring fish target strength are intercompared. The consistency of results obtained on the same or related species by different methods is noted. -
Target strength of polarized fish
Foote, Kenneth G. (ICES CM documents, Working paper, 1987)The effect of behaviour on target strength is simulated through computation of the average target strength with respect to a range of normal orientation distributions. The mean tilt angle is varied from -30 to 30 deg for ... -
Target strength of tiny roach
Foote, Kenneth G.; Lindem, Torfinn; Brabrand, Åge (ICES CM documents, Working paper, 1987)Seven frozen specimens of surface-adapted roach (Rutilus rutilus), of lengths 32-40 mm and masses 0.20-0.49 g, have been sectioned with a precision microtome. The swimbladder contours have been digitized and the swimbladder ... -
Target strengths of Antartic krill (Euphausia superba)
Everson, Inigo; Bone, Douglas G.; Watkins, Jonathan L.; Foote, Kenneth G. (ICES CM Documents;1988/B:6, Working paper, 1988)Encaged aggregations of swimming krill have been measured at 38 and 120 kHz. The results indicate that the target strength values are substantially lower than previously assumed. -
Three-in-one transducer design for a triple-frequencey echo sounder
Foote, Kenneth G. (ICES CM Documents;1989/B:8, Working paper, 1989)A design is outlined in which three different kinds of transducer elements are arranged concentrically and in near proximity. It will be possible to drive the elements simultaneously, thus forming three coaxial beams at ... -
Tilt angles of schooling penned saithe
Foote, Kenneth G.; Ona, Egil (ICES CM Documents;1985/B:26, Working paper, 1985)Saithe (Pollachius virens) of nearly uniform 32 cm length have been photographically observed during the daytime in an apparently free-swimming and schooling state in a pen of dimensions 90 m length, 10 m width, and 7 ... -
Trial of a New, Split-beam Echo Sounder
Foote, Kenneth G.; Kristensen, Finn Hogne; Solli, Haakon (ICES CM Documents;1984/B:21, Working paper, 1984)The first at-sea trial of a new, split-beam echo sounder, the SIMRAD ES380 system, is described following a review of the split-beam principle, outline of its realization in hardware and software, and description of ... -
Wideband beam pattern
Foote, Kenneth G. (ICES CM Documents;1989/B:2, Working paper, 1989)Transducer directivity is important in the basic acoustic surveying methods of echo counting and integration. In quantifying the directivity, the beam pattern is often computed assuming ideal single-frequency operation. ...