共查询到20条相似文献,搜索用时 46 毫秒
1.
我国天文气候特点及潜在(光学/红外)优良台址探讨 总被引:5,自引:0,他引:5
收集了我国1978-1986年和1990年,共10年时间的192个地面气象站每天四次总云量的观测资料,分别计算了北京时间08h,02h和08h以及20h,02h和08h的无云概率,分析结果表明:我国所处的天文气候条件的大环境并非是世界上最好的,但在国内相对较好的区域里,精心挑同受叶形得影响形成的较好台址还是有可能的。 相似文献
2.
3.
收集了我国1978─1986年和1990年,共10年时间的192个地面气象站每天四次总云量的观测资料,分别计算了北京时间08h,02h和08h以及20h,02h和08h的无云概率。分析结果表明:我国所处的天文气候条件的大环境并非是世界上最好的,但在国内相对较好的区域里,精心挑选出受局部地形影响形成的较好台址还是有可能的。 相似文献
4.
较详细地讲述了云南天文台三孔较差宁度监视仪的情况,然而,与一般天文理论和天文技术的专题研究不一样,天文仪器的研制有如说是研究,还不如说是归纳;它不是分析一个具体的沿示解决的难题,而是把许多已知的理论和技术综合起来,构成一台具体的仪器。所以,本文把许多至少是表面上互不相关的理论和技术问题归纳到一篇论文中。仪器是有许多模块组成的,为了起来逻辑性较强,我们将仪器分模块叙述,全文遵循如下顺序: 相似文献
5.
6.
7.
微温传感器测量近地面大气湍流分布的建议 总被引:1,自引:0,他引:1
根据大气湍流温度结构函数的基本定律,推导了用于测量近地面大气湍流强度分布以及对天文视宁度贡献的关系式;提出了进行该项测量的具体方案以及数据处理过程。 相似文献
8.
较详细地讲述了云南天文台三孔较差视宁度监视仪的情况,然而,与一般天文理论和天文技术的专题研究不一样,天文仪器的研制有如说是研究,还不如说是归纳;它不是分析一个具体的尚未解决的难题,而是把许多已知的理论和技术综合起来,构成一台具体的仪器。所以,本文把许多至少是表面上互不相关的理论和技术问题归纳到一篇论文中。仪器是有许多模块组成的,为了看起来逻辑性较强,我们将仪器分模块叙述,全文遵循如下顺序:1在第一篇中,回顾世界各天文台视宁度测量设备的发展史和云南天文台的宁静度测量发展史;2在第二篇中,介绍:1)云南天文台三孔较差视宁度研制任务的来源,仪器的整体状况;2)介绍云南天文台三孔较差视宁度仪的硬件系统;3)介绍云南天文台三孔较差视宁度仪的软件系统;若大模块中有多个小模块,在每一个大模块中,又遵循下述顺序:1)本模块的总体功能;2)构成该模块的基本技术;3)这些基本技术如何构成整体和完成预定功能。3在第三篇中,介绍我们所作的与视宁度测量有关的一些实验和实验结果。 相似文献
9.
10.
讨论了经过大气后天文图象的象质衰减,研究了对这种衰减进行描述的宁度参数r0及其它几个大气光学参数,介绍了几种测量象质衰减参数的方法,重点介绍了我们将差分像运动法运用于白日视宁度测量的尝试以及新设计的可兼顾昼夜的视宁度测量仪,仪器已用于云台白日的视宁度测量。最后对近场近似假设进行了定量分析,在此基础上给出新确定的近场近似成立的范围,这一范围比以前所给的要更大些。 相似文献
11.
《Chinese Astronomy and Astrophysics》2023,47(2):257-284
Atmospheric turbulence has been confirmed as the primary source affecting the quality of ground-based telescope image. To reduce the effect of atmosphere, a good site should be selected, and adaptive optics (AO) should be installed for the telescope. In general, the daytime atmospheric turbulence is more intense than that at night under the effect of solar radiation. Numerous solar telescopes have built AO systems worldwide. Conventional AO is only capable of improving the image quality in a small field of view, whereas it cannot satisfy the needs of a large field of view. The novel wide field adaptive optical system is capable of achieving a large field of view and high-resolution images, whereas the atmospheric turbulence profile should be accurately detected, which is the prerequisite and key parameter of the novel AO system. Moreover, the astronomical high-resolution technology in accordance with the turbulence imaging theory requires more detailed detection of turbulence. Accordingly, a brief review about the latest detection technology of the daytime optical turbulence profile is valuable for astronomical observations. Besides, the parameters of atmospheric turbulence are briefly introduced. Subsequently, SNODAR, SHABAR, MOSP, DIMM+, A-MASP, and other detection technologies of the stratified atmospheric turbulence for daytime are primarily presented, and the advantages and disadvantages of the different technologies are summarized. 相似文献
12.
Wang Hong-shuai Yao Yong-qiang Qian Xuan Liu Li-yong Wang Yi-ping Li Jun-rong 《Chinese Astronomy and Astrophysics》2013
The intensity and distribution of optical turbulence are important parameters to evaluate an observing station. A modeling method to obtain n atmospheric optical turbulence parameters, including the C2n pro?le, coherent length, coherent time, seeing, isoplanatic angle, and scintillation index by using meteorological parameters are presented. The accomplishment of this method, the con?guration of the WRF model (Weather Research and Forecasting Model), and the veri?cation of calculated results are introduced. The reliability of the method is con?rmed preliminarily by comparing the calculated results with the DIMM (Differential Image Motion Monitor) measurements. 相似文献
13.
14.
本文叙述了在天文选址定点观测中使用UBV三色光电测光系统测量大气透明度的最佳方法和所用到的各个计算公式,也包括了某些经验。 相似文献
15.
大气湍流理论的进展及其天文学意义(英) 总被引:2,自引:0,他引:2
传统的大气湍流理论始于大约30年前.湍流理论的发展使得天文学家对大气湍流对天文观测的影响有了很好的认识,尤其是它为天文台选址和天文高分辨率技术提供了基础.近年来新的天文观测已对传统的大气湍流理论提出了挑战,并可能给地面天文观测带来一场革命.在回顾了大气湍流理论的发展历史后对传统大气湍流理论的基本特性及其应用作了系统的综述,并介绍了新的天文观测事实以及为此而提出的新的大气湍流理论模型. 相似文献
16.
The site characteristics of Gulmarg, Kashmir at an altitude of about 2743.2 m above sea level is based on analysis of meteorological conditions, cloud cover, temperature, wind speed, wind direction, relative humidity and atmospheric pressure, etc. Analysis and characterization of meteorological conditions suggest that Gulmarg, Kashmir is a potential site for carrying out photometric as well as spectroscopic observations of celestial objects. 相似文献
17.
Through a comparison between the series expression and mapping function expression of the astronomical refraction, we believe that, as far as a specific atmospheric refraction model is concerned, the computational accuracy is not lower in the former than in the latter, and that the convergence is poorer in the theoretically derived series expression, because of the different approximations made. From an analysis of the method of generating function of the atmospheric refraction mapping function it is considered that this kind of method can not embody the characteristics of geophysics and atmospheric physics. It is pointed out from the comparison that the atmospheric refraction model which is constructed by adopting the specific atmospheric distribution of a certain place does not apply to all other places and cannot be used to evaluate the other atmospheric refraction models. For improving the correction accuracy the key lies in the adoption of an effective method by which the instantaneous refraction values at different positions are directly determined to construct a local, position-dependent model of atmospheric refraction observation. 相似文献
18.
地理信息是地面望远镜天文选址研究中的重要内容.尤其是对现有地理信息系统(Geographic Information System,GIS)的有效利用,已成为现代选址中远程分析阶段最重要的手段之一.天文址点的考虑在地理条件上应遵循以下原则:相对落差较大、交通可行、尽量远离人口集中的区域.从未来建站维护和人员长期驻站的角度考虑,天文址点以海拔处于3000~5000 m的范围、距离城镇大本营1 h左右车程为最佳.以云南省大姚县百草岭地区为选址研究对象,展示了GIS数据处理能够为全面了解一个候选区域3维地形地貌、江川河流、道路村落、电力分布以及预测该地区未来人口和城市化发展趋势等方面内容提供准确、直观、定量的参考数据.通过基于GIS数据的科学分析,发现海拔3 600多米的大百草岭山顶平坦而又干旱、周围人口稀少、道路便利、无工厂污染源,是地方政府重要自然保护区;它与直线距离10 km外的乡镇之间的相对落差超过了1 500 m,与50km外的县城的相对落差达到1 800 m,是滇中彝州坝区一座名副其实的孤峰.因此,GIS数据分析对于远程选址十分有益,GIS技术是现代天文选址不可或缺的重要手段. 相似文献
19.
20.
Yin Jia Yao Yong-qiang Wang Hong-shuai Li Lin You Xian-long Zhou Yun-he Ma Jiang-long Liu Li-yong Li Jun-rong Qian Xuan 《Chinese Astronomy and Astrophysics》2012
The cloudiness is one of the most important factors which affect the quality of an astronomical site, the monitoring and processing of the night- time cloudiness are especially important. The ground-based cloudiness camera is adopted to carry out the monitoring of the all-sky cloudiness, the images taken need to be processed by means of an effective method so as to quantize the cloudiness. The night-time cloudiness images are seriously affected by the moon- light, and therefore, the night-time cloudiness images are processed by dividing them into the moonlight and moonless two sorts. In the light of the condition of moonless night, the processing method of night-time cloudiness is given. The positioning and photometry of the bright stars in the image are conducted to determine their magnitude differences. By referring to the magnitude differences of the bright stars in the clear-night image, the probability of the bright stars of which the magnitude differences are lower than the threshold value are regarded as the probability standard of clear nights. Three sorts of images are selected to test the method. The cloudiness is determined, and the effect of the threshold condition on the result is analyzed. Finally, the applicable range and uncertainty of the method are discussed. 相似文献