An adaptable radio-controlled measuring system for oceanographic research in shallow water

The scientific objective of the system presented in this paper is to conduct in situ measurements of environmental parameters and to support several marine in situ experiments which are carried out in order to investigate the interaction between the sea and the sea bottom in shallow-water ecosystems. Automated in situ measurements are carried out by means of the radio-controlled data acquisition and control system "OBS" which is mounted on an unattended platform in the western Baltic. The shore station, at a distance of about 25 km, is located at the Institute of Applied Physics of Kiel University and is equipped with a central computer for real-time data retrieval and remote programming. Part of the OBS system is a vertical scanning profiling system which provides measurements of temperature, electrical conductivity, turbidity, scalar irradiance, downwelling and upwelling irradiance, pH, and dissolved oxygen in a water column of about 10-m depth. The vertical resolution is 10 cm. Profiling depth range was automatically determined from the shore by means of an adjustable upper depth limit, in order to protect the probes from surface waves. The research conducted here requires simultaneous measurements of various environmental parameters. This is done by about 20-30 fixed probes mounted on the platform in the air and in the water as well on the sea bottom in the neighborhood of the platform. The radio-controlled data acquisition system serves all probes and samples the sensors repeatedly in time.