Anglo-Australian Observatory
Seeing, the degradation of resolution due to the earth's atmosphere, is a crucial factor in determining the performance of ground-based telescopes. This degradation is predominantly the result of thermal inhomogeneity of the air, to which a substantial contribution arises from the diurnal cycle...
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Language: | English |
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.70.9372 http://www.phys.unsw.edu.au/~mgb/Antbib/anare_melb_prg2.pdf |
Summary: | Seeing, the degradation of resolution due to the earth's atmosphere, is a crucial factor in determining the performance of ground-based telescopes. This degradation is predominantly the result of thermal inhomogeneity of the air, to which a substantial contribution arises from the diurnal cycle of solar heating. In most of Antarctica the diurnal variation in temperature is negligible throughout winter, so good seeing can be expected on this account. Above the highest point of the Antarctic plateau the predominant air flow is a slow settling from the stratosphere which should promote extraordinarily uniform optical quality. Unfortunately, the lower boundary layer in which a strong inverse temperature gradient develops, especially in winter, is likely often to degrade what might otherwise be unprecedented seeing. Critical tests are needed to measure this degradation and determine whether it can be circumvented by mounting a telescope on a higher pier than usual. 28.1 THE IMPORTANCE TO ASTRONOMY OF GOOD SEEING For astronomy at wavelengths from the near-infrared (IR) up to a few mm, it is clear that high Antarctic sites, with their very dry cold atmosphere, offer the potential of enormous gains in |
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