Intercalibration of FY-3D MWTS Against S-NPP ATMS based on Radiative Transfer Model

Accurate calibration of satellite instrument is the premise of Earth geophysical parameter estimation. This paper presents the intercalibration of the Microwave Temperature Sounder (MWTS) on Fengyun 3D (FY-3D) against the Advanced Technology Microwave Sounder (ATMS) on Suomi National Polar-orbiting Partnership (S-NPP) satellite using microwave radiative transfer model fed with the fifth generation of European Centre for Medium-Range Weather Forecast (ECMWF) atmospheric reanalysis (ERA5) data. The results show that the calibration biases (mean ± standard deviation) are 1.83±1.45, 0.45±0.94, 1.87±0.60, 0.60±0.27, -0.02±0.37, 0.19±0.24, 1.69±0.28, 2.25±0.29, 1.97±0.33, 1.74±0.42, 2.84±0.42, 0.07±0.65, and 0.32±1.18 K in the thirteen MWTS channels, respectively. In addition, the results with the semi-empirical Land Surface Emissivity (LSE) model and the results with LSEs derived from ATMS observations are consistent, and the use of LSEs derived from ATMS observations for the rest of channels is feasible.