Evaluation of Finding Point Method for Fengyun-4A Satellite Infrared Longwave Remote Sensing

Recently, an automatic atmospheric radiation absorption parameterization scheme based on correlated k-distribution (CKD) has been proposed, namely, the finding point method (FPM). The FPM can avoid errors caused by manual operation and has higher accuracy when compared with other common CKD methods. In this paper, FPM is applied to the satellite brightness temperature simulation. In the simulation of the Fengyun 4A Advanced Geostationary Radiation Imager (AGRI), the root mean square errors (RMSE) of FPM in the brightness temperature simulation of the six infrared channels when compared with the standard result from the line-by-line integration are 0.1103, 0.2128, and 0.0459, 0.0266, 0.0328, and 0.1742 K, respectively, while the RMSE of Radiative Transfer for the Television Observation Satellite Operational Vertical Sounder (RTTOV) are 1.0879, 0.1120, 0.2204, 0.1567, 0.1164, and 0.3256 K, respectively. Therefore, FPM can achieve very good accuracy in satellite infrared remote sensing.