FY-4A卫星地表太阳辐射产品在河南省适用性评估与订正方法研究

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

以河南省26个地面辐射站观测的地面总辐照度逐小时数据为基准,对FY-4A反演的总辐照度产品在河南省的适用性进行验证分析,并采用概率密度函数方法,对FY-4A总辐照度产品的系统误差进行订正。结果表明,(1)FY-4A总辐照度整体大于地面观测结果,两者平均误差在豫南偏大、豫北偏小,而且从时间演变看,两者相对误差在冬半年偏小,夏半年偏大,这与云量、大气相对湿度等气象要素以及不同下垫面对FY-4A反演总辐照度的影响有关;(2)FY-4A卫星与地面观测的总辐射辐照度平均误差随不同辐照度等级而变化,整体呈现出一种非独立系统误差的特性,即对于低辐照度有所高估,而对于高辐照度则相对低估;(3)概率密度函数方法对FY-4A总辐照度具有较好的订正能力,在夏季以年为单位建立订正模型进行误差订正效果更好,在秋冬季以季节为时间尺度建立订正模型效果更好。

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.