Routine spectral wave data acquisition in OWS "Cumulus"

A number of research and survey vessels are fitted with shipborne wave records (SBWRs) which operate reliably with minimal servicing. In the past, the wave data have normally been logged as a time series, using central ship's computing facilities, or recorded by a simple chart recorder. This resulted in unacceptable post-processing delays and costs. This document describes an automatic logging/processing system which was installed and operated sucessfully for a number of years on OWS Cumulus, requiring manual intervention only at monthly intervals to download the processed data files. The system uses a dedicated personal computer, with analogue input card, to acquire and spectrally analyse the wave amplitude signal and to save the spectral data on hard disk. The document fully describes the hardware, software and operational requirements of the system.