12 December 1978 Calibration Of A Helium-Cooled LWIR Spectrometer For Exo-Atmospheric Airglow Measurements
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The calibration of a cryogenic infrared spectrometer is described. The calibration data are obtained in two facilities that simulate the vacuum and cold background of the upper atmosphere in an attempt to duplicate the conditions under which the measurements are to be made. These facilities provide for a distant small-area source and an extended-area source calibration. The sensor has a free spectral range of 7.3 to 22.7 µm, 2-3% resolution, a noise equivalent sterance (radiance) of about 4.5 x 10-11 W cm-2sr-1 µm-1 at 15 µm and obtains 2-scans/s. The measurement equation is derived from the calibration data as L(λ) = C(λ)[3.36 x 10-9 V + 1.1 x 10-12 V2] W cm-2 sr-1 µm-1 where C(λ) varies from unity upward, and the precision and accuracy are estimated at ± 7 to 12% and 13 to 16% (depending upon the wavelength) respectively.
© (1978) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Clair L. Wyatt, "Calibration Of A Helium-Cooled LWIR Spectrometer For Exo-Atmospheric Airglow Measurements", Proc. SPIE 0156, Modern Utilization of Infrared Technology IV, (12 December 1978); doi: 10.1117/12.956781; https://doi.org/10.1117/12.956781


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