These instruments measure pressure fluctuations, or the changing height of the water column, associated with passing waves. These pressure time series can be converted to sea surface elevations and wave frequency spectra. The shore stations store data continuously in digital memory. Arrays of four pressure sensors placed in a 6m square configuration provide directional information similar to that acquired by directional buoys. In addition to wave data, wind and temperature data are collected at some sites.
Sea temperature is measured either by buoys or by temperature gauges mounted to a pier.
Anemometers are used to collect wind data, which can be converted to average and maximum velocity. We have been fortunate to receive the cooperation of the US Coast Guard, local fishermen, and other marine community entities for the deployment of these instruments. All the instruments at a particular site are connected to a shore station, either by cable, cellular phone or radio link. The raw data from all of the instruments are archived on disk for access by CDIP clients. Analyzed data are sent in near real-time to the National Weather Service computers to aid in marine weather advisories and surf forecasts.