Data Acquisition Methods for Coastal Currents.

摘要

Design criteria for the type and location of coastal engineering structures depends heavily on the understanding of nearshore processes and the evaluation of the ranges of significant parameters such as waves, currents and sediment transport. Gauging of these parameters, in and around the zone of breaking waves has been difficult for the lack of rugged implements and instruments, mobility and adequate experimental designs. In answer to some of the previous shortcomings, a Towed Oceanographic Data Acquisition System (TODAS) has been developed for collection of nearshore current and wave data. The sensors are located on a mobile platform (the sea sled) and data acquired by them are telemetered to shore and digitally recorded. TODAS was designed for the real time evaluation of the characteristics of flow between shore and a depth of 30 feet, and because it is mobile and battery-operated it can be used to survey reasonably large areas at even remote locations. Two experimental designs were developed for TODAS; a mobile mode for the monitoring of waves and longshore currents in shore normal profiles, and an in-situ mode in which Eulerian and Lagrangian techniques of flow measurement are combined. In the latter, fixed point metering is supported by aerial photography and concentration measurements of dispersing dye plumes. (Author)