临边成像光谱仪是一种对大气遥感探测有重要研究和应用价值的新型空间光学遥感仪器。 信噪比是定量评价成像光谱仪成像质量和辐射性能的的一项重要指标， 信噪比的估算和测量对成像光谱仪的研制至关重要。 针对临边成像光谱仪从辐射传输和能量转换角度， 建立了信噪比模型， 推导了色散型临边成像光谱仪信噪比计算公式， 编制了信噪比快速计算程序。 利用大气辐射传输软件MODTRAN 4.0模拟计算出在典型观测条件下仪器入瞳光谱辐亮度， 从理论上估算了已研制成的临边成像光谱仪原理样机在典型观测条件下的信噪比。 结果表明， 在典型观测条件下原理样机的信噪比不低于8。 作为实验验证， 利用内照明积分球光源对临边成像光谱仪原理样机进行了信噪比测量， 测量结果证实了理论模型的正确性。

Limb imaging spectrometer is an important new remote sensor for research and application. Signal-to-noise ratio (SNR) is one of the key parameters to quantitatively evaluate the image quality and radiometric performance of an imaging spectrometer. The estimation and testing of SNR are very important for developing an imaging spectrometer. From the perspectives of radiative transmission and energy conversion, the SNR model is proposed, and the SNR equation of dispersive-type limb imaging spectrometer is derived, and the SNR values under several observing conditions for an limb imaging spectrometer prototype developed are theoretically evaluated based on atmospheric radiative transfer code MODTRAN 4.0. The results show that the SNR of the prototype under typical viewing geometry is not less than 8. As experimental validation, SNR testing was performed using an internally illuminated integrating sphere, and the experimental results have proved the correctness of this theoretical model.