Rocketborne far-infrared circular-variable filter spectrometer development

The report concerns the development of high-vacuum liquid-helium cooled circular-variable filter spectrometers. These spectrometers have been successfully used in rocketborne applications to make in situ measurements of the overhead spectral radiance, as a function of rocket height, of the atmospheric emission species in the long wavelength region of the infrared. This research led to the advancement of the state-of-the-art in such aerospace infrared measurements and in several related areas such as the detector-preamplifier interface and cold bearing design. A total of five rocket flights were conducted which resulted in measurements of the overhead radiance, as a function of rocket altitude between 45 and 200 km, of the atmospheric emissions in the 7 to 24 micrometer range of the infrared.