Interferometers
AERI
The AERI instrument is an advanced version of the high spectral resolution interferometer sounder (HIS) designed and fabricated at the University of Wisconsin (Revercomb et al. 1988) to measure upwelling infrared radiances from an aircraft. The AERI is a fully automated ground-based passive infrared interferometer that measures downwelling atmospheric radiance from 3.3 - 18.2 mm (550 - 3000 cm-1) at less than 10-minute temporal resolution with a spectral resolution of one wavenumber. Careful attention to calibration results in an absolute calibration accuracy of better than 1% of the ambient. The AERI instrument foreoptics consist of a scene mirror and two calibration blackbodies. These blackbodies are essential to provide a well known stable hot and ambient temperature reference for calibration of the downwelling skyview radiances. A typical measurement cycle consists of a three-minute sky dwell period followed by two-minute dwell periods for each of the blackbodies. While the interferometer acquires an uncalibrated spectrum every two seconds, averaging reduces the radiometric noise in the measurements. The temperature of one of the blackbodies is fixed at 60 oC, while the other fluctuates with the ambient temperature. More Information and data: "http://cimss.ssec.wisc.edu/aeri/" [Extracted from the AERI Homepage]