Multi-beam Echo Sounder for Fishery Research

Simrad and IFREMER (French Marine Institute) have developed a new multi-beam echo sounder for fishery research purposes. The first ME70 will be installed onboard French research vessel 'Thalassa'. Simrad is also working on a version for the IMR (Norwegian Marine Institute) for installation onboard 'GO Sars'. The multi-beam technology has several improvements compared to the traditional single beam methodology. It enables more accurate and flexible fish stock assessment providing increased sampling volume and improved input to stock estimate models. The ME70 can also “see” fish close to the sea bottom, which until now was considered a 'blind zone' for fishery research.

The new ME70 operates in 70 to 120 kHz frequency band with a configurable acoustic fan containing 3 to 45 stabilised beams. Each beam is from 2° - 3° wide depending on operational frequency, with a maximum total swath width of ±45°. Minimum acquisition depth is less than 1m below the surface and maximum acquisition depth is approximately 700m for a -20 dB single target and 800m for a -40 dB volume target. The system configuration can be tailored to any user requirements allowing for a choice of beam widths and transmission modes. It is possible to set-up continuous output of all beam data for use with echo integration and 3D visualisation. A real-time display enables quality control of current data acquisition. The ME70 is also configurable for two way remote control, enabling 'off-site' operation.