USE OF SINGLE-PING BOTTOM-TRACK ADCP DATA TO CHARACTERIZE SMALL-SCALEBATHYMETRY

A shipboard acoustic Doppler current profiler, in its bottom-track mod e, estimates the radial velocity of the transducer relative to the bot tom and the range from the transducer to the bottom for each beam of e ach ping. These data, along with attitude data (pitch, roll, and headi ng), can be used to map the X, Y, and Z positions of the beam/bottom i ntercepts. This paper shows how these intercepts can then be used to c haracterize the size, shape, and orientation of small-scale bathymetri c features. The method is applied to data collected over a field of sa nd waves located 40 km east-northeast of Cape Hatteras, North Carolina , in 30 m of water. Forty-five sand waves were crossed. The sand waves were oriented in an east-west direction, had characteristic heights o f 3 m, wavelengths of 230 m, and northern slopes steeper than southern slopes (e.g., 3.8% versus 2.4%). Some sand waves were sampled repeate dly and extended for several kilometers.