Mid-Infrared Observing Conditions at the South Pole
The Antarctic plateau is the optimum ground based site for infrared astronomy. Low levels of precipitable water vapour and high altitude combine to improve atmospheric transmission. Lower emissivity and cold temperatures produce lower background levels for infrared observations than possible at temp...
| Main Authors: | , , , , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2000
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.296.3700 http://www.phys.unsw.edu.au/jacara/Papers/pdf/asa98_mism.pdf |
| Summary: | The Antarctic plateau is the optimum ground based site for infrared astronomy. Low levels of precipitable water vapour and high altitude combine to improve atmospheric transmission. Lower emissivity and cold temperatures produce lower background levels for infrared observations than possible at temperate sites. Presented are interpretations of sky dip data and results quantifying the winter midinfrared (4 to 16 microns) sky background at the South Pole measured in 1998. They come from a mid-infrared sky monitor, the “MISM”, installed on the on the “AASTO” currently deployed by JACARA at the US Amundsen-Scott South Pole Station. The MISM records the differential flux of atmospheric emission between beams 45 degrees apart in the sky. Results are reduced to zenith flux by calibration with a black body, to yield the sky flux, atmospheric temperature and emissivity as a function of wavelength. Spectra are produced of the sky emission with a resolution of 2 % from 4 to 14 microns. Significant reductions from temperate sites are obtained. Figure 6 Calculated atmospheric emission spectra from overcast, moderately clear |
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