Applications
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Investigating the Ocean
Autonomous solutions for real-time environmental monitoring and decision support
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Subsea Leak Detection
Subsea leakage detection of oil and gas using passive and active acoustics is an emerging technology with promising outlook for many applications.
Expertise
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Acoustics
CMR have strong expertise within acoustics and apply this expertise in a wide range of application areas.
Projects
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Sailbuoy
The SailBuoy is part of new generation unmanned ocean vehicles designed for marine observations, enabling a persistent presence on the world’s oceans.
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NEXOS
New cost-effective, innovative and compact integrated multifunctional sensor systems
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BRIDGES
Bringing together research and industry for the development of glider environmental services
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LoVe
The Lofoten-Vesterålen Cabeled Ocean Observatory (LoVe) is a Norwegian infrastructure for marine research, monitoring and subsea technology development.
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AALDOG
Active Acoustic Leak Detection of Oil and Gas. A project funded by RCN through the DEMO 2000 program, and a project-cooperation between METAS and CMR, IMR, Simrad (Kongsberg Maritime) and Statoil.
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EXACTUS
Technologies, systems and operational procedures for high-level accuracy in biomass control in large cages
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Arctic Ice Edge Voyage
A new project will provide environmental data from ice edge zone in the Arctic.
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Sounds in the Ocean
Characterization and quantification of anthropogenic, biological and ambient sounds in the oceans are important for a range of marine industries as well as for enhancing our understanding of marine ecosystem.
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Autonomous surface vehicles for fish detection / Fiskeletende Autonome Overflatefarkoster
Fiskerinæringen bruker årlig store ressurser på fiskeleting, både for å finne ut hvor et innsig slår til og for å finne gode og riktige fangster på feltene. Autonome overflatefarkoster med et lavt energiforbruk har et stort potensial i leting og overvåkning for fiskerinæringen, og vil kunne gi pålitelig sanntids beslutningsstøtte før fangst. Teknologiutviklingen har nådd et punkt hvor denne typen overflatefarkoster er utprøvd og kommersielt tilgjengelig.
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Mobile acoustic observation methodologies for cabled ocean observatory transects
The scientific idea of Lofoten-Vesterålen cabled ocean observatory (infrastructure project, LoVe) is to establish real-time monitoring that produces four-dimensional properties of observations along the observatory transect (depth • distance from coast • time • flux of observed quantities). The project aims to be an operational framework which in turn will facilitate continuous monitoring of water and biomass flux along the coast by the Norwegian costal and Atlantic currents, thus connecting processes at the coast with those taking place in northern oceans. Such a perspective requires observations also in-between the stationary cable nodes, and a spatial interpolation model that utilizes all available observations to give the best possible information at the transect along the cable
Publications
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Fish finding with autonomous surface vehicles for the pelagic fisheries
Øyerhamn, Rune; Kolltveit, Erling; Pedersen, Geir;
Unused or unmanaged catch represents more than 40 % of the global marine catches. Autonomous systems for search and detection may reduce the environmental footprint of commercial fisheries by improving the targeting accuracy and also reduce the amount of fossil fuels that today are consummated by conventional fishing vessels during their search for fish.
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Modeling target strength of individual herring (Clupea harengus) at any aspect as a function of pressure and frequency
Fish target strength is primarily dependent on the physical dimensions of the fish, the acoustic frequency, and the orientation of the fish. In traditional vertically observing echosounder surveys, fish are insonified in the dorsal aspect with fairly limited tilt angle variation. In oblique-angled sonar surveys, however, fish may be insonified at other aspects.
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Relative acoustic frequency response of induced methane, carbon dioxide and air gas bubble plumes, observed laterally.
Rokas Kubilius; Pedersen, Geir;
There is an increased need to detect, identify, and monitor natural and manmade seabed gas leaks. Fisheries echosounders are well suited to monitor large volumes of water and acoustic frequency response [normalized acoustic backscatter, when a measure at one selected frequency is used as a denominator, r(f)] is commonly used to identify echoes from fish and zooplankton species.
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Simulation of acoustic backscattering from bubbles and droplets under different shape regimes with implications for underwater detection of leakages using active acoustic sensors.
Safe subsea production of oil and gas, as well as storage of CO2 in geological formations subsea, require rapid detection of accidental releases, eliminating potential harm to the environment. Monitoring of natural gas seeps are important in a climate and environmental aspect.
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Advances in the use of active acoustics for detection and conservation of cetaceans
Bernasconi, Matteo; Pedersen, Geir; Patel, Ruben; Nøttestad, Leif; Brierly, Andrew S.
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Lateral aspect acoustic frequency response of gas bubble plumes
R. Kubelius; Pedersen, Geir; T. Torkelsen
Laterally observing fisheries echosounders are useful in specific applications, such as to inspect surface blind zones from a vessel, to observe wild fish gathering under fish-farm nets or for bottom-mounted acoustic landers with both vertical and horizontal acoustic beams. The frequency response (r(f)) measured from the dorsal aspect is frequently used to identify species, but it is not clear if dorsally measured r(f) is useful for identifying laterally observed fish. The r(f) of free-swimming wild saithe was measured with stationary and laterally oriented split-beam echosounders at 70, 120, 200, 333 kHz, suspended in mid-water (22 m, bottom depth 41 m).
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Sailbuoy Unmanned Surface Vehicle as an active acoustic measurement platform for biomass detection and monitoring; sensor integration, tests, and demonstration mission
Pedersen, Geir; Peddie, David; Eliassen, Inge Kristian; Heggelund, Yngve; Lied, Gaute Øverås; Korneliussen, Rolf
The Sailbuoy is a low cost autonomous ocean platform capable of deployments for extended periods of time, and part of a new generation of vehicles designed for marine observations enabling scientists to expand and intensify the study and monitoring of seas and oceans.
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Active Acoustic Detection of Subsea Oil and Gas Leaks; Model Prediction and Measurements
Pedersen, Geir; Øyerhamn, Rune; R. Kubilius, and T. Torkelsen
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Accuracy of the Kirchhoff-approximation and Kirchhoff-Ray-Mode Fish Swimbladder Acoustic Scattering Models.
Pedersen, Geir; Gavin J. Macaulay, Héctor Peña, Sascha M. M. Fässler, Egil Ona
The acoustic backscatter from pressure release prolate spheroids and a three-dimensional representation of a fish swimbladder (Chilean jack mackerel, Trachurus symmetricus murphyi) was calculated using four target strength models (Kirchhoff-approximation, Kirchhoff-ray-mode, finite element solution of the Helmholtz equation, and prolate-spheroid-modal-series).
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A revised length to TS estimate for blue whiting (Micromesistius poutassou) and implications for biomass estimates
Pedersen, Geir; Gavin Macaulay; Gavin Macaulay; Olav R. Godø; Egil Ona
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A revised target strength–length estimate for blue whiting (Micromesistius poutassou): implications for biomass estimates
Pedersen, Geir; Olav Rune Godø; Egil Ona; Gavin J. Macaulay
Acoustic abundance estimates of blue whiting have generally been higher than estimates based on catch data. One explanation has been that the relationship between acoustic target strength (TS) and length is too low and hence overestimates the number of fish.
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Estimating tail-beat frequency using split-beam echosounders
Nils Olav Handegard; Pedersen, Geir; Ole Brix
Data from a standard split-beam echosounder are used to estimate tail-beat frequency within a dense herring (Clupea harengus L.) layer. The data were collected by lowering a horizontally projecting 38 kHz split-beam transducer into a herring layer at 245-m depth. Individual targets were concatenated into tracks, and a fast Fourier transform was used to estimate the periodogram of the backscattering strengths along each track.
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Modelling of sandeel (Ammodytes marinus) target strenght. Underwater Acoustic Measurements: Technologies & Results
Egil Ona; Pedersen, Geir;
Acoustic target strength of sandeel (Ammodytes marinus) was computed using a finite element approach. Target strength was found as a function of fish tilt-angle and acoustic frequency, and was computed from three-dimensional reconstructions of the fish form. Sandeels lack swimbladder and are small perch-like fish that bury in the bottom substrate.
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Target strength of some standard, and so me not - so - standard, targets in fisheries acoustics using the finite element method
Pedersen, Geir; Penã, H.; Ona, E.
The finite element method (FEM) is used to calculate target strength of standard targets in fisheries acoustics as a function of frequency and incident sound angle. These targets include spheres, spheroids, and cylinders using different boundary conditions, representing different physical properties of the scatterer. Target strength is also calculated for swimbladder models, chilean jack mackerel (Trachurus symmetricus murphyi), obtained from magnetic resonance imaging.
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Update on the calibration topic group
Pedersen, Geir; Toby Jarvis
Toby Jarvis gave an update on the status of the calibration topic group with specific reference to documenting the calibration procedure of the Simrad EK60 echosounder. The report of the topic group will be posted on the WGFAST web site and made available to the planning groups. The calibration topic group has now concluded with a key outcome that a calibration study group is formed with the intention of commencing at the 2010 WG FAST meeting in San Diego.