Assessment and correction of calibration consistency in medium resolution imagers’ split-window channels using Dome C

Accurate radiometric calibration consistency is fundamental for quantitative remote sensing retrievals using multi-source sensors. Previous studies have mainly evaluated inter-sensor calibration consistency (e.g., MODIS and VIIRS) but lacked systematic corrections. Such inconsistencies can propagate into long-term climate data records, leading to systematic uncertainties in temperature and radiative flux retrievals. Therefore, developing a robust correction framework to ensure multi-sensor consistency remains an urgent challenge. This study corrected calibration biases in the thermal infrared split-window channels of FY-3D/MERSI-II, FY-3E/MERSI-LL, and Aqua/MODIS using long-term observations over Dome C, Antarctica (2019–2024). Taking advantage of the homogeneous surface characteristics and minimal atmospheric interference at Dome C, Automatic Weather Station (AWS) temperature data were used as a proxy to calculate the fluctuation trends of relative biases for assessing calibration stability and ensuring the comparability of near-nadir satellite observations acquired at different times. This study reveals stable long-term seasonal variations in low-end calibration biases over years, showing a consistent linear relationship with brightness temperatures from 190 to 250 K. After correction, inter-sensor biases were reduced to near-zero levels with minimal temporal drift (within ± 0.02 K), significantly improving the reliability of multi-sensor data integration for quantitative applications in global climate studies.