Blar i Articles på emneord "acoustics"
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Acoustic abundance estimation of midwater animals
(Journal article; Peer reviewed, 1999) -
Acoustic observations of jellyfish in the Namibian Benguela
(Journal article; Peer reviewed, 2001-01-26)Multi-frequency acoustic data (18, 38 and 120 kHz) were collected in conjunction with pelagic trawl sampling for gelatinous macrozooplankton during a cruise to the Namibian Benguela in September 1999. Sampling focused ... -
Acoustic resonance determination of the rigidity modulus
(Others, 2001) -
Acoustic sampling volume
(Journal article; Peer reviewed, 1991)Knowledge of the acoustic sampling volume is necessary in many quantitative applications of acoustics. In general, the sampling volume is not merely a characteristic of the transmitting and receiving transducers, but also ... -
Acoustic sampling volume
(Others, 1989) -
Acoustic scattering models of zooplankton
(Others, 1991) -
Antarctic krill swarm characteristics in the Southeast Atlantic sector of the Southern Ocean
(Journal article; Peer reviewed, 2012-09-28)Knowledge about swarm dynamics and underlying causes is essential to understand the ecology and distribution of Antarctic krill Euphausia superba. We collected acoustic data and key environmental data continuously across ... -
Averaging of fish target strength functions
(Journal article; Peer reviewed, 1980)A general model for averaging the acoustic target strength functions of fish is stated in calculable form. It accounts for the influences of the distribution of generally coupled spatial and orientation states of fish, ... -
Behavior of individual mesopelagic fish in acoustic scattering layers of Norwegian fjords
(Journal article; Peer reviewed, 2008-05-22)Mesopelagic acoustic scattering layers (SLs) in 2 fjords were studied from a stationary research vessel. Diel vertical movements of SLs were assessed by hull-mounted transducers, while in situ behavior of individuals ... -
Behavioral responses of herring (Clupea harengus) to 1–2 and 6–7 kHz sonar signals and killer whale feeding sounds
(Journal article; Peer reviewed, 2009-01)Military antisubmarine sonars produce intense sounds within the hearing range of most clupeid fish. The behavioral reactions of overwintering herring (Clupea harengus) to sonar signals of two different frequency ranges ... -
Bioacoustics and D. V. Holliday: a scientific tribute
(Others, 2004) -
Can predator avoidance explain varying overwintering depth of Calanus in different oceanic water masses?
(Journal article; Peer reviewed, 1999-04-15)Distributions of overwintering Calanus spp. in the upper 1000 m in the Norwegian and Greenland Seas were studied in relation to hydrography, invertebrate predators and acoustic scattering layers (38 kHz). C, finmarchicus ... -
Can the precision of bottom trawl indices be increased by using simultaneously collected acoustic data? The Barents Sea experience
(Journal article; Peer reviewed, 2007-12)Acoustic data are recorded continuously during the winter survey for demersal fish in the Barents Sea. This paper presents a method for using the information from the acoustic recordings between trawl stations in an attempt ... -
Correcting acoustic measurements of scatterer density for extinction
(Journal article; Peer reviewed, 1990)Extinction is sometimes a major problem in acoustic surveys of fish stocks, as it often occurs when the fish are concentrated and easiest to survey. The same may be true of certain macrozooplankton, such as krill in swarms. ... -
Detecting Atlantic herring by parametric sonar
(Journal article; Peer reviewed, 2010-03-17)The difference-frequency band of the Kongsberg TOPAS PS18 parametric sub-bottom profiling sonar, nominally 1–6 kHz, is being used to observe Atlantic herring. Representative TOPAS echograms of herring layers and schools ... -
An effective method for the recapture of escaped farmed salmon
(Journal article; Peer reviewed, 2011-04-04)The search for effective strategies to prevent and mitigate accidental releases of aquaculture fishes is on-going. To test a new recapture strategy and evaluate the individual dispersal behaviour of escaped farmed Atlantic ...