A Study for the Determination of Kompsat i Crossing Time Over Korea(i); Examination of Solar and Atmospheric Variables

Abstract

Korea Multi-Purpose Satellite I(KOMPSAT-I, the first multi-purpose Korean satellite) will be launched in the third quarter of 1999, which is operated on the sun-synchronous orbit for cartography, ocean color monitoring, and space environment monitoring. The main mission of Electro-Optical Camera(EOC) which is one of KOMSAT-I sensors is to provide images for the production of scale maps of Korea. EOC collects panchromatic imagery with the ground sample distance of 6.6m at nadir through visible spectral band of 510-730nm. For determining KOMSAT-I crossing time over Korea, this study examines the diurnal variation of solar and atmospheric variables that can exert a great influence on the EOC imagery. The results are as follows: 1)After 10:30 a.m. at the winter solstice, solar zenith angle is less than 70 and expected flux of EOC spectral band over land for clear sky is greater than about 2.4mW/cm2. 2)For daytime the distribution of cloud cover(clear sky) shows minimum(maximum) at about 11:00 a.m. Although the occurrence frequency of poor visibility by fog decreases from early morning toward noon, its effect on the distribution of clear sky is negligible. From the above examination it is concluded that determining KOMSAT-I crossing time over Korea between 10:30 and 11:30 a.m. is adequate.