Ye Han-Han, Wang Xian-Hua, Wu Jun, Fang Yong-Hua, Ma Jin-Ji, Jiang Xin-Hua, Wei Qiu-Ye
Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2013 Aug;33(8):2182-7.
Retrieving atmospheric CO2 concentration from space-based infrared measurements is an ill-posed problem, and the uncertainty of ground properties is an important impacting factor. For the requirement of high precision retrieval of atmospheric CO2, the effects of surface reflectance must be corrected. Thus a surface reflectance correction method is proposed. In this correction method, the selection of non-CO2 absorption (off-line) channel is an important part, so several different types of off-line channels were compared and analyzed. We finally found that averaging all data of multi-channels as off-line channel is the best way, in which the retrieval precision is highest and dispersion is lowest, because the advantage is that averaging many data can reduce random error. The effects of surface reflectance on CO2 retrieval decreased significantly after correction using ratio spectrometry combined with the selected off-line channel, and CO2 retrieval precision improved greatly.
从星载红外测量中反演大气二氧化碳浓度是一个不适定问题，地面特性的不确定性是一个重要影响因素。对于高精度反演大气二氧化碳的需求，必须校正地表反射率的影响。因此提出了一种地表反射率校正方法。在这种校正方法中，非二氧化碳吸收（离线）通道的选择是一个重要部分，所以对几种不同类型的离线通道进行了比较和分析。我们最终发现，将多通道的所有数据进行平均作为离线通道是最佳方法，其反演精度最高且离散度最低，原因是平均多个数据的优势在于可以减少随机误差。使用比率光谱法结合所选离线通道进行校正后，地表反射率对二氧化碳反演的影响显著降低，二氧化碳反演精度大幅提高。
