Determination of sunglint location and its characteristics on observation from a METEOSAT 9 satellite

Abstract

On the basis of observations from a geostationary satellite, a method for the determination of sunlight location on the ocean surface, based on two parameters – (1) the Greenwich time and (2) the longitude of the satellite – was developed. The problem is solved in three stages: first, the position of the Earth in its orbit for any given point of time is determined; second, for this point of time, the relative position of Sun–Earth–satellite is defined; and, third, the latitude and longitude of the principal point of sunglint (PPS) was found. The outputs of the program based on this method are: (1) the geographical coordinates of PPS; (2) the boundary of a simultaneously illuminated and observed region of the Earth; (3) the contour of the sunglint (disk) on the smooth ocean surface; and (4) the distribution of the sunglint brightness on the rough (waved) ocean surface. This method is applied to detect sunglint characteristics in the images gathered from the METEOSAT 9 satellite.