Trawl-safe profiler development at SACLANT Centre for shallow water environmental assessment and real time modeling

A Shallow-water Environmental Profiler in Trawl-safe, Real-time configuration (SEPTR) has been developed by SACLANT Undersea Research Centre in support of oceanographic modeling and rapid environment assessment programs. It is being deployed operationally for the first time during September 2000 as part of real-time multi-scale oceanographic modeling experiments in the Ligurian Sea. The SEPTR system combines the best capabilities of the Barny Sentinel ADCP bottom platform and the SWEEP water column profiler developments at SACLANT Centre. It is intended for 3-6 month deployments in areas where water column instruments are at risk from fishing trawlers, but with real-time data return and control via two-way cellular or satellite communication. SEPTR includes a micro-controller based bottom platform which houses an Acoustic Doppler Current Profiler (ADCP), wave/tide gage, ambient noise sensor array, and water column profiler buoy system. The profiler buoy system has an independent microcontroller with its own sensor suite. Communications and battery recharge from the bottom platform are supplied through the 2 mm diameter cable. The profiler requests winch operations from the bottom electronics for autonomous vertical profiling of CTD and optical properties of the water column in depths down to 100 m. Cable and profiler drag permit profiling with currents up to 2 knots at 50 m depth and 1 knot at 100 m depth. The profiler buoy includes DGPS navigation capability along with two-way communication capability while on the surface. It also includes acceleration and magnetic field sensors capable of surface wave buoy measurements.