基于FY-4 AGRI与Himawari-8 AHI的平均太阳光谱辐照度研究

Study on average solar spectral irradiance based on FY⁃4 AGRI and Himawari⁃8 AHI

文中选取ASTM-E490太阳光谱来计算AGRI和AHI数据的可见光和近红外波段的ESUNb值,并经已发布ESUNb值的HJ-1A/1B CCD1传感器验证了计算值的可靠性,最后将其应用于数据的预处理中。结果表明:通过ASTM-E490太阳光谱计算得到了AGRI和AHI数据可见光和近红外波段的ESUNb值可用于AGRI和AHI数据预处理中;经验证,基于ASTM-E490太阳光谱计算得到的ESUNb值与官方值的绝对误差在10以内,相对误差仅在0.191%~0.571%之间;计算得到的ESUNb值可用于数据的预处理中,经定标和大气校正后发现,校正后影像的对比性更清晰,且AGRI数据的地物边界更为清晰,变化更加明显。

The ASTM⁃E490 solar spectrum is chosen to calculate the ESUNb values for the visible and near⁃infrared bands of AGRI and AHI data,the reliability of the calculated value is verified by the HJ⁃1A/1B CCD1 sensor with the published ESUNb value,and then it is applied to the data preprocessing.The results show that the ESUNb values for the visible and near⁃infrared bands of AGRI and AHI data obtained by the ASTM⁃E490 solar spectrum calculation can be used in the AGRI and AHI data preprocessing;the absolute error of the ESUNb value calculated based on ASTM⁃E490 solar spectrum with the official value is within 10,and the relative error is only between 0.191%and 0.571%;the calculated ESUNb value can be used in the data preprocessing,the clearer contrast of the corrected images are revealed after the calibration and atmospheric correction,and the object boundary of the AGRI data is clearer and the changes are more pronounced.