| The Fengyun-3（FY-3）meteorological satellite plays a very important role in China’s meteorological satellite industry,which can monitor the large-scale natural disasters together with surface ecological environment,proving various meteorological and geophysical parameters for the climate prediction.The Medium Resolution Spectral Imager（MERSI）,mounted on the FY-3D satellite,is a key remote sensor for the Earth’s atmospheric,terrestrial and oceanic data.Since the accuracy of the remote sensor is particularly important for the quantitative application of subsequent observation data,the calibration research with a sub-channel and sub-pixel is performed for the remote sensor using the FY-3D/MERSI lunar observation data,improving the calibration method of the domestic satellite.The specific research contents and innovations are as follows:In view of the actual physical scene of the earth-moon space,the observable time points of the moon are calculated by the Python program under four moon observation conditions.The observed time points are reverse-checked by satellite simulation software STK,and the four conditions are checked correctly,indicating that the prediction model has a high degree of fitting with the actual situation.This can prepare for the subsequent operation of the calibration model and irradiance calibration model.After completing the prediction of lunar observation time,the results of the prediction model are adopted to screen and extract the lunar images,and the observation results are corrected by the Python program.Combined with the correction coefficient exported by the lunar correction model,the remote sensor is calibrated on the basis of the lunar irradiance model.Finally,a long time series of the calibration coefficient is obtained using the lunar observations with the MERSI 250 resolution and 1000 resolution,respectively.Although there are some fluctuations in some regions,the long time series of calibration coefficients at MERSI 250 and 1000 resolutions tend to be stable in general. |
