| 摘要 |
<p>Systems and methods for acquiring accurate maps of near-shore depth and surface currents are disclosed. An imaging platform is provided which is able to obtain a time series of overhead images of an area of a body of water having pixel intensity correlated with wave height. The platform may be on a tower, or may be airborne, space-borne, or ship-borne. The imaging modality may be optical, radar, or LIDAR. Image processing corrects the images, as and if needed, such they are mapped onto a grid of fixed coordinates, and the pixel intensities have a near linear relationship to wave height. A two-dimensional Fourier transform of each image is obtained, then the extremum of an objective function is found, wherein the objective function is a function of the depth and surface current (velocity) vector at each pixel location, and the extremum is sharply peaked at a particular set of depth and a particular set of surface current vector values. A pixel-by-pixel map of depths and or currents can be produced.</p> |
