【摘要】 在洁净海洋上空,卫星遥感器在可见光谱区中接收到的信号主要来自于大气分子散射。根据大气辐射传输机理利用观测海洋的方法,对星载遥感器的可见和近红外通道进行绝对辐射定标。为了克服大气气溶胶散射对辐射定标精度的影响,利用组合可见和近红外通道同时观测高亮云层和洁净海面对NOAA-14 AVHRR作出了精确的辐射定标。而Landsat-5 TM遥感器,由于飞行前标定辐射设置过低,无法使用高反射目标进行辐射定标。本研究利用大气散射辐射以及大气和海洋宏观平均特征进行辐射定标,同样得到了好的结果。为了证实定标结果,与中国格尔木沙漠地区的光谱反射率实际测量进行了对比。更多还原

【Abstract】 The contribution from atmospheric molecular scattering is prevailing to the signal received by the satellite sensors in visible spectrum over the clear ocean. Based on the mechanism of radiative transfer in the atmosphere, the present paper applies the approach using clear ocean view to calibrate absolutely visible and near-infrared sensors on satellites. To eliminate the effect of atmospheric aerosol scattering on the accuracy of the calibration both AVHRR channels 1 and 2 over the ocean and over high bright clouds are used simultaneously. However, because the upper limit on the post-calibration radiance for all Landsat-5 TM channels may be set too low, the high reflective targets can not be used for calibration. The calibration for TM channels are performed by use of atmospheric scattering and averaged ocean data in this paper. To verify the results of the absolute calibration derived by the above approach the data of spectral reflectivities measured in Ge-Er-Mu desert area are applied for comparison.更多还原