Edwards D P, Gille J C, Bailey P L, Barnett J J
Appl Opt. 1995 Oct 20;34(30):7006-18. doi: 10.1364/AO.34.007006.
We describe the scientific design work behind the selection of the IR spectral passbands for the 21 sounding channels of the High Resolution Dynamics Limb Sounder (HIRDLS), which is scheduled to fly aboard the Earth Observing System chemistry platform at the beginning of the next century. At least one radiometer channel must be used for each gas that is being measured. Preferably the interfering contributions to the radiance by other gases in a channel should be small, but the principal requirements are that the desired emission be measured with high signal-to-noise ratio and that there be separate channels for the measurement of interfering species. However, more than one channel is required for providing full altitude coverage of those target gases such as CO(2), H(2)O, and O(3), which have emission bands whose centers become optically thick in the middle atmosphere. Further channels, in which gaseous absorption is low, are required for the characterization of aerosol effects. We describe the HIRDLS channels selected for each gas, with emphasis on signal-to-noise considerations and altitude coverage, the elimination of contaminating signal between channels, and nonlocal thermodynamic equilibrium processes for high-altitude sounding and space view definition.
我们描述了高分辨率动力临边探测仪（HIRDLS）21个探测通道红外光谱通带选择背后的科学设计工作，该仪器计划于下个世纪初搭载在地球观测系统化学平台上飞行。对于每一种被测量的气体，至少必须使用一个辐射计通道。理想情况下，通道中其他气体对辐射率的干扰贡献应该很小，但主要要求是能够以高信噪比测量所需的发射，并且要有单独的通道来测量干扰物种。然而，对于那些目标气体，如二氧化碳（CO₂）、水（H₂O）和臭氧（O₃），由于它们的发射带在中层大气中中心变得光学厚度很大，需要不止一个通道来提供其完整的高度覆盖范围。为了表征气溶胶效应，还需要气态吸收低的其他通道。我们描述了为每种气体选择的HIRDLS通道，重点是信噪比考量和高度覆盖范围、消除通道间的污染信号，以及用于高空探测和空间视图定义的非局部热力学平衡过程。
