Ten-Bands Ocean Color and Temperature Scanner

Abstract

China has developed ocean observation satellite named HY-1A. This satellite has been launched in 05/2002 with meteorological satellite FY-1D. 10 bands ocean color and temperature scanner and 4 bands CCD imager was mounted on HY-1A. In this paper we introduce the 10-bands ocean color and temperature scanner which has 10 bands from visible to thermal infrared and the ground resolution is 1.1km at the nadir (orbit altitude = 798 Km). 4 elements detector array is used for every band in order to improve detecting sensitivity and a "K" mirror is used to eliminate image rotating on the focal plane caused by 45deg scanning mirror. HY-1A launched with FY-1 which altitude is 870 Km and incidence is 98.8deg. Because the descending crossing time of FY-1 is about 8:35 a.m., so it is not good for ocean observation. Therefore, HY-1A changed its altitude from 870 km to 798 km in order to improve the illuminance of the earth surface. HY-1A moved round the earth 14.3 cycles a day and will be able to cover the earth surface entirely in three days when the FOV of the scanner is plusmn35deg. As the reflectance of ocean is very low, 4 elements detector array is used for every band to improve detecting sensitivity and a "K" mirror is used to eliminate image rotating on the focal plane caused by 45deg scanning mirror. Table 1-Table 3 list some important parameters of the 10-bands ocean color and temperature scanner.