Current measurement technology for near-shore waters

This paper summarises recent experiences (in SCAWVEX and elsewhere) in measuring near-shore currents, together with subsequent techniques of data analyses. In situ instrumentation described includes: mechanical rotors, electromagnetic and ADCP (Acoustic Doppler Current Profiler) deployed on sea bed frames, in towed mode, and mooring lines. Surface observations from the: Ocean Surface Current Radar (OSCR) H.F. radar system are also included. Deployments are in estuaries, along open coasts and in tidal straits-all involving strongly tidal regimes around the UK coasts. The characteristics, including specific capabilities and limitations of each instrument are listed. Synoptic comparisons are used to illustrate those components such as the depth mean principal tidal constituents: which show good agreement and to highlight other components, e.g., vertical profiles of residuals, most sensitive to the system adopted. A coordinate system suitable fur analysing net fluxes in shallow estuary with large tides is described. Associated aspects, which impact on planning current meter deployments, are outlined. (C) 1999 Elsevier Science B.V. All rights reserved.