Sonars

Description

Scientific multi beam sonar: The Scientific Multi Beam sonar shall be delivered and installed complete. The transducer will be mounted in the side of the vessel drop keel. It should deliver calibrated water column backscatter data for modern 3D measurements of fish and makrozooplankton (krill and amphipods) schools, measured away from the path of the vessel, especially close to the surface layer in the echo sounder acoustic blind zones. The system will be used for abundance estimation of schools and layers, mainly in open ocean conditions. The systems must comply with the following standards: — Measure simultaneously in a cubic beam fan covering a horizontal sector at least 60 degrees and a vertical sector of 45 degrees divided in 500 beams (25 by 20), with high individual beam resolution to a range of about 500 meters. — Frequency (fish and macro zooplankton): 75 — 112 kHz. — Calibration of individual beams should be enabled to standard split beam methods. — For improved signal-to-noise ratio, individual beam side lobe suppression should enable a two-way side lobe level of -35 dB in the vertical direction and better than -17 dB in the horizontal direction. — For simultaneous measurements of strong (Bottom echo) and weak (zooplankton echoes and noise) at the same setting, a documented high dynamic range in amplitude, at least better than 120 dB. — For external control: Remote controlled operation and user defined data subscription. — For automatic compensation of vessel movement: input and storage of data from scientific high precision motion reference units. — Automatic stabilization for roll movement. — Possibilities of input and display from other auxiliary instrumentation, like trawl or towed gear. — Data output in format .raw must be available for post processing purposes. Scientific multi beam echo sounder: The Scientific Multi Beam Echo Sounder shall be delivered and installed complete with transducer mounted in the vessel drop keel is delivering calibrated water column backscatter data for modern 2D measurements of fish and makrozooplankton (krill and amphipods), schools and layers. Abundance estimation of these in open oceans and inside ice conditions with the vessel moving at standard surveying speed or in stationary situations are typical results. The systems must comply with the following standards: — Measure simultaneously in a vertical beam fan of at least 60 degrees perpendicular to the ship sailing direction at the frequencies 70 to 120 kHz, for an effective range of at least 300 m. — Up to 45 beams in the fan with an individual beam opening of minimum 2 degrees. — Calibration of individual beams should be enabled to standard split beam methods. — For improved signal-to-noise ratio, individual beam side lobe suppression should enable a two-way side lobe level of -35 dB in both along ship and athwart ship directions. — For comparisons with standard echo sounders, user defined, selectable reference beams with close to normal scientific echo sounder beam operation should be available. — For external control: Remote controlled operation and user defined data subscription. — For automatic compensation of vessel movement: input and storage of data from scientific high precision motion reference units. — Possibilities of input and display from other auxiliary instrumentation, like trawl or towed gear. — Data output in format .raw must be available for post processing purposes. — For simultaneous or alternate operation as bottom mapping system, bathymetric options should be available.