1.Key Laboratory of Infrared System Detection an Imaging Technology， Chinese Academy of Sciences， Shanghai 200083， China;2.Shanghai Institute of Technical Physics， Chinese Academy of Sciences， Shanghai 200083， China;3.University of Chinese Academy of Sciences， Beijing 100049， China
Supported by National Key R&D Program of China （No. 2018YFB0504900； No. 2018YFB0504900）
The three elements of water color remote sensing products are chlorophyll， suspended substance and yellow substance. As one of the main loads of HY-1 satellite， Chinese Ocean Color and Temperature Scanner （COCTS） has set up 8 visible and near-infrared detection channels， to provide primary data for the study of global ocean primary productivity distribution. HY-1B COCTS was launched in 2007， and at the beginning of orbit entry there exists light pollution in cold space which works as the zero-radiation datum， which leads to the signal cut-off in the deep-sea area of the near-infrared detection channel， and the lower the latitude， the bigger the cold air signal is. In order to study the mechanism of the problem and repair the historical data of HY-1B COCTS， the characteristics of the source of the problem was verified in the laboratory， and the influence mechanism was analyzed. Based on the relationship between the sun glint energy of HY-1C COCTS and the solar zenith angle， the sun glint energy of HY-1B COCTS at different solar zenith angle is calculated. According to the radiometric calibration coefficient， the corresponding code value of the sun glint energy and the correction quantity can be obtained. The results show that the correction quantity is linear with the energy calculated from the solar zenith angle， and can be used to repair other target signals of HY-1B COCTS. This algorithm can be used to repair the remote sensing data of nearly 9 years of HY-1B COCTS. It lays a theoretical foundation for data comparison between the same kind of ocean remote sensing instrument and retrieving water color products.
FAN Wen-Long, HUANG Xiao-Xian, FU Yu-Tian. Analysis of radiation reference anomaly of HY-1B COCTS and research on the repair algorithm[J]. Journal of Infrared and Millimeter Waves,2022,41(1):310~321Copy