Calculations of the radiance distribution of solar highlights on the surface of the ocean when they are observed from geostationary orbit

Abstract

This article describes methods of calculating the radiance distribution of solar highlights on the ocean surface and of determining the contour of the image of the solar disk on the smooth surface when it is observed from geostationary orbit. The radiance of the reflected radiation is calculated by the method of stochastically distributed small areas, taking into account shading on an uneven surface, as well as the sphericity of the terrestrial sphere. The results of the calculations show that the size of the surface region covered by solar highlights, as well as the radiance distribution of the highlights inside this region, depend on both the irradiation-observation geometry and the degree of oceanic waviness (i.e., the wind speed). The radiance map is analyzed, and maps of lines of constant radiance are given for various geometries and wind speeds. (C) 1999 The Optical Society of America. [S1070-9762(99)02512-9].