Development of a Low-Cost Tide Gauge

Abstract

A low-cost tide gauge was developed and field tested to demonstrate a technology that would enable more cost-effective and greater sampling of spatially variable water levels and ocean surface waves. The gauge was designed to be adaptable to expendable and, possibly, air-deployed use for applications such as support of naval operations. The gauge incorporates a single printed circuit board that includes a very low power 3.3-Vdc microprocessor and 1 Mbyte of nonvolatile flash memory. A low-cost solid-state pressure sensor provides pressure data that are corrected automatically as a function of measured pressure and temperature and are processed within the gauge to provide low-frequency water levels and nondirectional surface wave information. Gauge-operating lifetimes range from more than four months to more than two years, depending on the data collection mode (tide or tide?wave) and the data collection interval (half-hourly or hourly). Gauge measurements are compared to measurements from a Sea-Bird Electronics, Inc., wave and tide gauge that uses a high quality quartz sensor.