An overview of SEPTR: Shallow Water Environmental Profiler in a Trawl-Safe Real-Time configuration

An increased demand for shallow water current measurements, as a result of both military and environmental interest in littoral water activity, has recently accelerated the technological evolution of ADCPs. Long term (several months) deployments of ADCPs in heavily fished coastal waters are now relatively common. This paper describes the work conducted at NURC since the 90´s in the field of trawl-safe ADCP platforms. This includes both the Barny Sentinel model and its more recent real-time evolution into the SEPTR that adds an automated water column profiler, additional sensors and two-way communication at regular intervals. 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 satellite communication. SEPTR includes a micro-controller based bottom platform which houses an ADCP, wave/tide gage, ambient noise sensor array, and a water column profiler buoy system. The profiler performs autonomous vertical profiling of CTD and Fluorometer-Scattering Meter within the water column at depths down to 100m. Two-way communication of data, position and control allows profile results to be returned in near-real time, and operational commands together with profile schedules to be sent to multiple profiler instruments.