Spar Buoy Design for the Measurement of Centimeter-Scale Surface Waves in theDeep Ocean

摘要

A free-drifting buoy has been designed which incorporates an array of capacitancewave gauges, an anemometer, compass, and a vertical accelerometer. The buoy is intended to drift free of the influence of an attending ship and collect a log high frequency wave data for verification of radar remotely sensed imagery. Data collected is used to derive energy directional wave spectra for wavelengths between 10 and 100 cm and wave slope statistics for wave scales larger than 10 cm. The first and only Synthetic Aperture Radar (SAR) placed in earth orbit by the U.S. was launched by NASA in 1978. The satellite was SEASAT, a system of sensors designed to survey the earth's oceans. The SEASAT SAR produced images which were rich in detail and surprisingly coherent over tens of kilometers. Many of the features (for examples, see Fu and Holt, 1982) that were revealed remain unexplained today. Since the radar is sensitive only to the surface waves, these waves must be undergoing modulation by the underlying current structure and/or overlying atmosphere in order to produce such coherent patterns. The scale of the waves which give rise to the backscatter are on the same scale. Keywords: Radar backscatter from sea ice. (jd)