A vertical profiling system for making oceanographic measurements in coastal waters

A permanently deployed profiling instrument system offers advantages over conventional oceanographic data collection techniques, which include ship based towed and profiling systems and moorings with instruments at discrete depths. A profiling system provides extensive data throughout the water column at time intervals not easily achievable with the conventional techniques. Two profiling instrument systems have been deployed since August 1996 approximately nine kilometers off the coast of New Jersey in fifteen meters of water. They are part of the Long Term Environmental Observatory instrument system linked by an electro-optic seafloor cable to a shore station operated by the Rutgers University Institute of Marine and Coastal Science. An Internet connection provides researchers around the world access to the real-time data. Without limitations on power consumption typical of a battery powered instrument, the vertical profiling system was robustly designed for reliability and longevity. The major components include a buoyant instrument frame, the electromechanical cable, an electric motor driven winch and a cable tension compensation system which permits deployment to the surface in moderate waves. Either automatic or manual operation is selected by technicians at the shore station. Operational variables include ascent and descent rate, depth range and profiling frequency. A complete description of the profiling system, it's operation and performance is presented.