Accession Number : ADP000384

Title :   Subsurface Wave-Measuring Systems,

Corporate Author : SHELL DEVELOPMENT CO HOUSTON TEX

Personal Author(s) : Forristall,George Z.

Report Date : NOV 1982

Pagination or Media Count : 16

Abstract : Pressure transducers were one of the first means used to measure waves in coastal waters. Nevertheless, some stigma has been attached to their use, since the wave signal is attenuated by overlying water. In some investigations, the correction for this attenuation has not been done, or has been done improperly. Contemporary high-resolution instruments and digital data processing techniques can now be used to get accurate wave data in many situations. An intercomparison between a wave staff and a pressure transducer mounted 56 ft below mean water level was conducted at the Buccaneer platform in February 1980. The analysis showed that spectral methods could be used to convert the pressure record to wave height for attenuation factors up to about 10 to 1. Fast-response current meters can be used in conjunction with pressure transducers or wave staffs to estimate the directional wave spectrum. In the past few years, this technique has become more or less routine. Some recent examples include the Ocean Test Structure experiment to study wave forces on platforms, a fatigue-monitoring program at the Cognac platform, an experiment to study the attenuation of waves propagating over a soft muddy bottom, and a tripod used for study of the bottom boundary layer. (Author)

Descriptors :   *Ocean waves, Height, Orientation(Direction), Measurement, Measuring instruments, Underwater equipment, Dynamic pressure, Ocean currents

Distribution Statement : APPROVED FOR PUBLIC RELEASE