Radar Remote Sensing of Ocean Surface Currents and Waves

The processes of erosion and sediment transport determine the bathymetric evolution of natural beaches. The alongshore transport of sediments and pollutants in the surf zone is primarily driven by mean currents with the circulation often characterized by mean longshore flows. These flows are affected by local bathymetry, spatial, and temporal changes in incident wave energy and direction. Capturing the spatial and temporal variations in mean flows in the surf zone is key to predicting the morphological change of the nearshore topography and shoreline. Much of the field research in the nearshore zone has been accomplished with in-situ measurement techniques requiring a substantial number of instruments to adequately sample the scales associated with nearshore circulation. Remote sensors are less invasive, are generally easier to deploy and maintain, and offer wider areal coverage than typical arrays of in-situ instruments. The text presents a comparison of two remote sensing techniques, microwave radar and optical video, used to infer nearshore surface currents. It also introduces engineers and scientists to the wide variety of applications of remote sensing in the nearshore zone.