云南天文台大气视宁度测量

Measurements of Atmospheric Seeing in Yunnan Observatory

利用大气相干长度和等晕角测量仪（CLIAM）和长焦照相拖影装置，于1992年11～12月期间在云南天文台太阳山头测量了大气视宁度。结果表明，大气相干长度和星像抖动约方根值之间具有很明显的相关性。另外还用温度脉动探空数据对CLIAM的结果作了比较，证明两者在定量上符合很好。全部2208个大气相干长度数据的统计特性呈现极好的正态分布，其中值为12．67cm，其标准差为4．453cm。从定性上说，在云南天文台晴朗或部分晴朗的夜间有85％的概率出现好的或很好的大气视宁度。

Using the Coherence Length and Isoplanatic Angle Measurer(CLIAM) and a long-focus star trail photographic device, the atmospheric seeing is measured at Mount Sun, Yunnan Observatory during Nov. to Dec. 1992. It is shown that there is an obviouscorrelation between the atmospheric coherence and the RMS of image motion. In addition, the balloon sounding data of temperature fluctuation are used to check the results of theCLIAM, and they are cobndsistant quantitatively. A total of 2208 data on atmospheric coherence indicates a very well normal distribution with a median TO~ 12.67 cm and astandard deviation σ = 4.453 cm, showing qualitatively the atmospheric seeing in Yunnan Observatory is good or very good with a probability of 85% in clear and partly clear nights.