Icosahedral-gnomonic projection and grid of the world ocean for wave studies

Abstract

The world ocean has been mapped in a special projection, icosahedral-gnomonic, which is optimized for wind-wave studies. The map allows for relatively simple propagation of the waves. The graticule of the map has been computed in detail. The inverse function describing geographical coordinates in terms of map coordinates has been derived and used to tabulate grid point locations for a world network; the function describing great circle track adjustments on any icosahedral-gnomonic projection has been derived and tabulated. This projection features segmented straightline representation of great circles and small simple distortions of direction and scale. Large parts of the globe can be represented without interruption, and a regular, nearly equidistant grid can be fitted over the globe. This projection should be useful in other problems, especially problems involving great circles.