共查询到17条相似文献，搜索用时 125 毫秒
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介绍了丽江高美古二期选址在踏勘和筛选工作的基础上，对3^#点和6^#点的视宁度进行了对比观测。通过对1999年2月6日－1999年12月31日2个点共4756组同时段观测数据的统计和处理得到：3^#点的视宁度平均值为11.2623cm，6^#点的视宁度平均值为11.5952cm。经F分布检验和t分布检验假设成立，作出3^#和6^#点的视宁度无显著性差异的推断，与初期用衍射环观测视宁度的结果一致，进一步说明了高美古整个山头的视宁度都是优良的。 相似文献
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丽江高美古的二期选址—筛选点的筛选 总被引：1，自引：1，他引：0
介绍了丽江高美古二期选址的筛选工作，经过踏勘确定高美古周围山头的10个点为筛选点，采用小型轻便望远镜于1998年10月16至1999年1月27日进行目视衍射环观测，并对取得的资料作了处理、分析和初步探讨，观测发现各点的视宁度没有明显差别，6#点的视宁度略好于其它点，说明高美古的整个山头有较好的视宁度。 相似文献
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云南天文台丽江高美古和昆明的大气视宁度研究 总被引：5，自引：1，他引：4
研究云南天文台昆明凤凰山和丽江高美古两地点的大气视宁度。利用云南天文台于1994年建立的3孔较差视宁度监视仪（3孔DIMM），对这两个地点的视宁度对比观测。还利用云南天文台的1米望远镜所得到的视宁度与3孔DIMM所测的视宁度进行对比。1米望远镜和3孔DIMM同时观测了7个晚上，各取得308组数据，它们的视宁度平均分别为0．90〃和0．84〃。还讨论了3孔DIMM采用不同曝光时间对视宁度测量值的影响，从实验得出3孔DIMM采用20ms曝光比采用8ms曝光所测视宁度的值要好15％左右。从1995年5月－1996年12月，对丽江高美古和昆明凤凰山二地进行了视宁度的对比观测。在高美古和昆明分别观测了234夜和256夜，观测结果是两个点的视宁度平均；丽江为0．70〃，昆明为0．95〃，同时也统计了两个点的月平均视宁度和最好夜的视宁度，并讨论了两地视宁度随时间的变化规律。 相似文献
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介绍了丽江高美古二期选址的筛选工作，经过踏勘确定高美古周围山头的10个点为筛选点，采用小型轻便望远镜于1998年10月16至1999年1月27日进行目视衍射环观测，并对取得的资料作了处理、分析和初步探讨。观测发现各点的视宁度没有明显差别，6 相似文献
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丽江高美古的天文观测条件 总被引：6，自引：0，他引：6
综述对丽江高美古的视宁度、天光亮度、消光系数进行观测的原理、仪器、观测方法和结果．结果表明,高美古是我国南方的优良光学天文台址,视宁度达到世界优良台址的水平 相似文献
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给出丽江高美古天文候选点两年的湿度观测结果与宾川３００２ｍ山峰的比较,初步分析了湿度对天文可用时间及视宁度的影响。 相似文献
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通过对新月和满月夜期间测光夜数和云量统计数的比较, 高美古的天文测光夜数和可用夜数与丽江县的气象晴日数的比较, 以及在同样的观测时间高美古和丽江县云量观测值的比较, 本文对高美古选址云量观测可靠性的有关方面进行了讨论 相似文献
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A deep ROSAT PSPC image centred on the Orion Trapezium has been reduceda second time using an improved version of the PSF to fit the data. The outer rim of the field of view was also included. The new catalogue contains 316 X‐ray sources which are easily identified with pre‐main sequence stars of the Ori OB1 Ic and Id association. All 316 sources were tested for variability. No variations were found inside the single exposures of about 45 minutes length each. Between the 4 exposures spaced over 5 days about 1/3 of the sources show signs of activities of various forms. As above 25% of these have somewhat regular lights curves (monotonically rising or falling or hill‐shaped) we infer that at least some outbursts with time scales longer than a day are present and that past searches for X‐ray flares of pre‐main sequence stars were biased towards shorter time scales. 相似文献
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Pei Chong Yuan Xiang-Yan Chen Hua-Lin Zhao Jian-Lin WEN Hai-Kun Li Zheng-Yang 《Chinese Astronomy and Astrophysics》2012
The Antarctic site-testing campaigns have shown that Dome C is an excellent astronomical site on the earth, it is better than any of existing mid-latitude astronomical sites in the world, because of its cold and dry weather, low infrared background radiation, continuously observable time as long as 3–4 months, clear and highly transparent atmosphere, low wind speed, and the absence of dust and light pollution. And in the international astronomical community it is generally believed that Dome A with a higher altitude may be better than Dome C as a potential excellent astronomical site. In the past 3 years, although held by the Center for Antarctic Astronomy of Chinese Academy of Sciences, the site testing at Dome A has preliminarily con?rmed the many advantages of Dome A as an excellent astronomical site, but the data about the atmospheric seeing, which is an important parameter for assessing the site quality for optical observations, have not been obtained until now. Hence, on the basis of a commercial telescope with the diameter of 35 cm, we have made the hardware reformation and software development to have it operate as a DIMM (Differential Image Motion Monitor), which can simultaneously monitor both the seeing and isoplanatic angle at Dome A automatically. At present this instrument has been shipped to Antarctica by the “Xuelong” exploration ship, and will be installed at Dome A, and begin to work in early 2011. Before the shipment, by through the comparative measurements together with an existing seeing monitor at the Xinglong astronomical station, the software, hardware, as well as the installation and adjustment of the instrument, are further veri?ed by testing. 相似文献