Analysis of Nighttime Infrared Cloud Cover at Yaoan Astronomical Station
Abstract
Clouds have important effects on astronomical observations. Cloud cover is an important indicator of the quality of an astronomical site. The infrared cloud imager which locates in Yaoan astronomical station, is used for the real-time acquisition of all-sky infrared cloud image with high spatial resolution. Combining the actual observations of space debris, according to astronomical nights strictly, we make statistics and analysis of cloud cover at night accumulated in one year (from 2015-08-01 to 2016-07-31). Annual average cloud cover at night at Yaoan astronomical station is 4.42 ten percent, and there are 236 available astronomy nights, including 98 photometric nights, 44 half-photometric nights, and 94 spectroscopic nights. The cloud cover has obvious characteristics of two seasons: the rainy season with a significant increase in cloud cover is from May to October, and the observation conditions are worst in July; The dry season is from November to April with low cloud cover, there are more than 23 available astronomy nights monthly, the most numerous photometric nights are in January, and the most available astronomy nights are in March. Combined with the threat level of cloud for astronomical observation, we make statistics of the total time of different cloud covers and the monthly distribution of cloud covers, to assess the meteorological conditions of the station, and to provide a reference for reasonable arrangements of the astronomical observations.
- Publication:
-
Acta Astronomica Sinica
- Pub Date:
- March 2017
- Bibcode:
- 2017AcASn..58...13F
- Keywords:
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- astrometry;
- instrumentation: infrared cloud imager;
- telescopes;
- techniques: image processing;
- methods: observational;
- data analysis