Assessment of the Applicability and Calibration Methods of FY-4A Satellite Surface Solar Radiation Products in Henan Province

Based on the hourly data of total irradiance observed by 26 ground radiation stations in Henan Province， the paper verified and analyzed the applicability of FY-4A inverted total irradiance products in Henan Province， and The Probability Density Function Matching Method was used to correct the systematic error of the FY-4A total irradiance product.The results showed that： （1） The total irradiance of FY-4A was greater than that of ground observation， and the average error of the two was larger in southern Henan and smaller in northern Henan.Moreover， from the perspective of time evolution， the relative error of the two was smaller in the winter half year and larger in the summer half year， this was related to the influence of meteorological elements such as cloud cover， relative humidity of atmosphere and different underlying surfaces on the total irradiance retrieved by FY-4A.（2） The average error of total irradiance of FY-4A satellite and ground observation varied with different irradiance levels， showing a non-independent systematic error as a whole， that was， it overestimated low irradiance and underestimated high irradiance.（3） The Probability Density Function Matching Method had a good correction ability for the total irradiance of FY-4A， and it was better to establish a revised model on an annual basis in summer to correct the error， and in autumn and winter， it was better to establish a revised model with the season as the time scale.