High Resolution Measurements of Turbulence, Velocity and Stress Using a Pulse-to-Pulse Coherent Sonar

Abstract

Abstract Considered are the capabilities of a recently developed pulse-to-pulse coherent sonar called the High Resolution Current Profiler (HRCP). Special emphasis is placed on methods whereby reliable and accurate vertical profiles of turbulence parameters, such as turbulent kinetic energy and Reynolds stresses, may be extracted from such sonars. The prototype HRCP has been developed in order to obtain precise and reliable measurements of both the mean and the fluctuating components of the velocity vector profile in the bottom boundary layer (lowermost 10 m). The prototype HRCP developed through the project BSEX is a 307 KHz pulse-to-pulse coherent sonar with four beams mounted 30° off the vertical in 90° azimuthal increments. It has 50 range cells covering a vertical profiling distance of 10 meters. The data collected are radial speeds along the four acoustic beams. Thus, care has to be exercised in interpreting the measurements in terms of turbulence parameters. It is shown, based upon reasonable assum...