Remotely controlled profiling system for measurements in shallow water

Abstract

An automatic profiling system is used to measure environmental processes such as the vertical transport of matter and the interaction between the upper and the lower layers and the sea-bottom in the western Baltic. One version of this system is mounted on a remote unattended platform and is part of a radio controlled data acquisition and control system. The shore station, at a distance of about 25 km, is located in the Institute of Applied Physics of Kiel University and is equipped with a central computer for real time data retrieval and remote programming. In this version of the profiling system the emphasis is on 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 to 30 fixed probes mounted on the platform in the air and in the water as well as on the sea-bottom in the neighbourhood of the platform. The radio controlled data acquisition system serves all probes and samples,the sensors repeatedly in time.