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介绍了利用AQUA卫星高光谱AIRS资料对FY-1C、FY-1D气象卫星热红外通道进行交叉定标的方法及定标结果。首先利用卫星轨道预报软件预报出AQUA与FY-1C以及AQUA与FY-1D卫星交叉点,再对交叉区域卫星资料进行像元投影和像元匹配,像元匹配包括时间、观测角度、环境均匀性等检验。以AIRS探测结果作为辐射基准,利用其观测值和FY-1卫星热红外通道光谱响应函数进行光谱匹配,最终得到FY-1卫星热红外通道的准真值并与FY-1卫星的业务产品进行比较分析。对FY-1C、FY-1D两年多卫星资料进行多次交叉比对,结果表明FY-1C通道4比AIRS观测亮温低1.3K左右,通道5低3.6K左右;而FY-1D通道4比AIRS观测亮温低0.3K左右,通道5低3.6K左右。这个准真值与FY-1观测的计数值进行再定标得到新的定标系数。
The method of cross-calibration of FY-1C and FY-1D meteorological satellite thermal infrared channels by AQUA satellite hyperspectral AIRS data and the calibration results are introduced. Firstly, satellite orbit prediction software is used to predict the intersection of AQUA, FY-1C and AQUA with FY-1D satellite. Then the pixel projection and pixel matching of the satellite data in the cross-region are performed. The pixel matching includes time, observation angle and environmental uniformity Other tests. Using AIRS detection results as the radiation reference, spectral matching between the observations and the FY-1 satellite thermal infrared channel spectral response function was performed to obtain the FY-1 satellite thermal infrared channel’s quasi-truth value and to be used with the FY-1 satellite business products comparative analysis. Multiple cross-comparison of FY-1C and FY-1D satellite data for more than two years showed that the FY-1C channel 4 was about 1.3K brighter than AIRS and the channel 5 was about 3.6K lower, whereas the FY-1D channel 4 Than the AIRS observation of low temperature about 0.3K, channel 5 low 3.6K or so. This pseudo-true value is then rescaled from the observed value of FY-1 to obtain a new scale factor.