Dome C coherence time statistics from DIMM data
International audience We present a reanalysis of several years of DIMM data at the site of Dome C, Antarctica, to provide measurements of the coherence time τ 0. Statistics and seasonal behaviour of τ 0 are given at two heights above the ground, 3m and 8m, for the wavelength λ = 500nm. We found an...
Published in: | Monthly Notices of the Royal Astronomical Society |
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Main Authors: | , , , , , |
Other Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2020
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-02890504 https://hal.archives-ouvertes.fr/hal-02890504/document https://hal.archives-ouvertes.fr/hal-02890504/file/Aris_tau0_arXiv.pdf https://doi.org/10.1093/mnras/staa1862 |
Summary: | International audience We present a reanalysis of several years of DIMM data at the site of Dome C, Antarctica, to provide measurements of the coherence time τ 0. Statistics and seasonal behaviour of τ 0 are given at two heights above the ground, 3m and 8m, for the wavelength λ = 500nm. We found an annual median value of 2.9ms at the height of 8m. A few measurements could also be obtained at the height of 20m and give a median value of 6ms during the period June-September. For the first time, we provide measurements of τ 0 in daytime during the summer, which appears to show the same time dependence as the seeing with a sharp maximum at 5pm local time. Exceptional values of τ 0 above 10ms are met at this particular moment. The continuous slow variations of turbulence conditions during the day offers a natural test bed for a solar adaptive optics system. |
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