说明：  绝对定标：通过各种标准辐射源，在不同波谱段建立成像光谱仪入瞳处的光谱辐射亮度值与成像光谱仪输出的数字量化值之间的定量关系
(Absolute calibration: The quantitative relationship between the spectral radiance value of the imaging spectrometer at the entrance of the imaging spectrometer and the digital quantized value output by the imaging spectrometer is established by various standard radiation sources.)