临边观测是一种新的空间大气遥感探测方式， 但大气散射光谱辐射随临边高度的增加而迅速减弱。 所以信噪比是临边遥感仪器的关键性能指标。 在深入分析典型仪器信号光谱辐射传输特性和噪声来源的基础上建立了随探测器制冷温度变化的信噪比模型， 并在一台临边遥感光谱仪原理样机上模拟试验验证了空间环境下临边高度70 km处的信噪比， 理论分析和实验结果一致表明: 探测器制冷到一定温度时， 仪器的信噪比达到了一个极限值。 在综合考虑功耗、 散热等问题的基础上获得了探测器的最优工作温度。

Limb viewing is a new viewing geometry for space-based atmospheric remote sensing, but the spectral radiance of atmosphere scattering reduces rapidly with limb height. So the signal-noise-ratio (SNR) is a key performance parameter of limb remote sensor. A SNR model varying with detector’s temperature is proposed, based on analysis of spectral radiative transfer and noise’ source in representative instruments. The SNR at limb height 70km under space conditions was validated by simulation experiment on limb remote sensing spectrometer prototype. Theoretic analysis and experiment’s results indicate congruously that when detector’s temperature reduces to some extent, a maximum SNR will be reached. After considering the power consumption, thermal conductivity and other issues, optimal operating temperature of detector can be decided.