Atmospheric temperature sensing with a multiorder Fabry-Perot interferometer.

A Fabry-Perot interferometer has a periodic response. By matching the free spectral range of a Fabry-Perot interferometer (FPI) with the period of the CO(2) spectrum, considerable advantages of throughput and spectral resolution can be achieved, leading to high spectral resolution and vertical resolution for atmospheric temperature sounders. In this paper, the concept of a high resolution multiorder Fabry-Perot interferometer using portions of the 15-microm and 4.3-microm bands of CO(2)for the purpose of atmospheric temperature sounding is discussed. Suitable sounding spectral positions, FPI free spectral range, and weighting functions are calculated. An effective spectral resolution of 0.02 cm(-1) can be achieved by the proposed sounder with a FPI finess of ~100 which is within the present state-of-the-art technology in the infrared region, leading to considerable improvement in the vertical resolution of the atmospheric temperature sounder.