A high-resolution wave-sensor array for measuring wave directional-spectra in the nearshore zone

A high spatial-resolution, multiple wave-sensor array recently deployed in the nearshore breaking-wave zone is described. The system is believed unique in terms of its resolving capability for directional wave spectra and its comprehensive scope. The array is a crossed "T" configuration of 30 metres aperture, using 14 wave-sensor elements spaced as a broadband detection ensemble. The wave array spreading function is briefly discussed. The wave sensor used was a teflon capacitance wavestaff of high linearity, accuracy, and stability. Laboratory calibrations are presented and a system error budget developed. The sensors were sampled at 5 SPS and the data was digitally recorded on magnetic tape with the data acquisition system reported in Ocean's '76. A low sea-state record and an initial field record of a well-developed storm episode recorded in January, 1977 are shown. Wave heights of up to 6 metres (20 feet) crest-to-trough were measured during the latter event.