Blar i Brage IMR på tidsskrift "The Journal of the Acoustical Society of America"
Viser treff 41-60 av 84
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First data from sea trials with the new MS70 multibeam sonar
(Journal article; Peer reviewed, 2006) -
The fish swimbladder as an acoustic waveguide
(Others, 2001) -
Fish target strengths for use in echo integrator surveys
(Journal article; Peer reviewed, 1987)In situ measurements of fish target strength are selected for use in echo integrator surveys at 38 kHz. The results are expressed through equations in which the mean target strength TS is regressed on the mean fish length ... -
Further analysis of target strength measurements of Antarctic krill at 38 and 120 kHz: Comparison with deformed cylinder model and inference of orientation distribution
(Journal article; Peer reviewed, 1993)Data collected during the krill target strength experiment [J. Acoust. Soc. Am. 87, 16–24 (1990)] are examined in the light of a recent zooplankton scattering model where the elongated animals are modeled as deformed finite ... -
Geographic variation and acoustic structure of the underwater vocalization of harbor seal (Phoca vitulina) in Norway, Sweden and Scotland
(Journal article; Peer reviewed, 2004)The male harbor seal (Phoca vitulina) produces broadband nonharmonic vocalizations underwater during the breeding season. In total, 120 vocalizations from six colonies were analyzed to provide a description of the acoustic ... -
High-resolution target strength measurements in deep water
(Others, 1999) -
Hydroacoustic performance of fishery survey instruments
(Others, 2001) -
Importance of the swimbladder in acoustic scattering by fish: A comparison of gadoid and mackerel target strengths
(Journal article; Peer reviewed, 1980)Previous determinations of the swimbladder contribution to the fish backscattering cross section have been hindered by ignorance of the acoustic boundary conditions at the swimbladder wall. The present study circumvents ... -
The influence of wind-induced bubbles on echo integration surveys
(Journal article, 1981)An investigation of attenuation of acoustic energy caused by gas bubbles in the surface layers has been carried out. This was done primarily to study the effect on echo integration of fish abundance when using hull-mounted ... -
Linearity of fisheries acoustics, with addition theorems
(Journal article; Peer reviewed, 1983)An experiment to verify the basic linearity of fisheries acoustics is described. Herring (Clupea harengus L.) was the subject fish. Acoustic measurements consisted of the echo energy from aggregations of encaged but otherwise ... -
Maintaining precision calibrations with optimal copper spheres
(Journal article; Peer reviewed, 1983)Effects of variations in quantities influencing the backscattering cross sections of solid elastic spheres are studied through a particular case. This is that of the 60-mm-diam copper sphere, which is being used worldwide ... -
Measurement of fish target strength with a split-beam echo sounder
(Journal article; Peer reviewed, 1986)Data derived with a 38-kHz split-beam echo sounder have been analyzed to yield target strengths suitable for use with echo integrators. This has required compensation for both thresholding and saturation, since these ... -
Modeling the target strength of Calanus finmarchicus
(Others, 1999) -
Modeling the target strength of Meganyctiphanes norvegica
(Others, 1999) -
Observing individual fish behavior in fish aggregations: Tracking in dense fish aggregations using a split-beam echosounder
(Journal article; Peer reviewed, 2007)Acoustic instruments are important tools for observing the behavior of aquatic organisms. This paper presents a simple but efficient method for improving the tracking of closely spaced targets using a split-beam echosounder. ... -
Observing the behavioral response of herring exposed to mid-frequency sonar signals. (A)
(Conference object, 2010-03)There is general concern on how mid-frequency military sonars might affect aquatic animals. Approaches used to investigate possible effects on Norwegian spring spawning herring (Clupea harengus) are presented. Experiments ... -
Optimizing copper spheres for precision calibration of hydroacoustic equipment
(Journal article; Peer reviewed, 1982)n operational definition of backscattering cross section is developed for the wideband reception of finite echoes. This is supported by relative measurements on a set of copper spheres by each of four echo sounders operating ... -
Parametric acoustic array and P. J. Westervelt: A tribute
(Others, 2006) -
Performance of the parametric receiving array: Effects of misalignment
(Others, 1987)The difference frequency sound field from two concentric but misaligned, axisymmetric, planar transducers in a nondissipative and nondispersive medium is developed as a special case of the general theory [Garrett et al., ...