基于嵌入式系统的望远镜远程控制实验

为了验证通过网络进行天文望远镜控制的技术,及通过嵌入式Internet对现场总线设备进行远程控制的可行性,本实验以嵌入式Internet开发板TINI为平台,通过一组应用程序的开发,实现了对一台配备有伺服控制系统的小型业余天文望远镜的远程控制和状态监视。     

用于2.4m望远镜的网络气象站

在进行天文观测时,天气因素的影响是很大的,为适应天文观测技术发展的要求,在2.4m镜附近需要建立一个网络气象站,一方面可以对天气状况实时监测,另一方面其他设备可以从网上查询并使用这些数据,以满足2.4m望远镜必须要有气象状况输入才能正常地在RoboticMode下工作的要求。文中介绍了1 wirenet气象站的原理以及软硬件设计。     

天文文献全文检索系统的研究与实现

介绍在对全文数据库和全文检索有关技术研究分析的基础上,以天文文献作为处理对象,开发Internet网络环境下基于Lucene检索引擎的天文文献全文检索系统,实现了无需后台数据库的天文文献全文检索系统。全文检索系统在网络环境下运行。     

安全网络授时服务技术研究

网络时间协议(NTP)是一种非常重要的互联网授时方法。目前,基于NTP的网络授时系统已经在互联网上被广泛应用。但是NTP在快速发展的同时也暴露出很多安全性问题。根据网络时间协议的安全需求针对性地加入安全算法,对于提高网络时间服务系统的安全性十分重要。文章首先介绍了网络时间协议的基本工作原理,分析了网络时间服务系统存在的安全漏洞,介绍了NTP安全模型。其次,实现了客户端和服务器软件,并在此基础上加入RSA算法,确保NTP数据包在传输的过程中不会被截取和更改。利用实验数据,对加入RSA算法后的网络时间服务系统性能进行了详细分析。最后阐明了安全性对于网络时间服务体系的重要意义。     

在SCO UNIX环境下开发实时通信系统

在SCO UNIX环境下开发实时系统，不仅可以利用UNIX的多任务特性，建立起高效可靠的系统，而且软硬件成本较低。还能享有商业软件的技术服务。介绍了基于SCO UNIX环境开发实时通信系统时多路串行通信技术及UDP网络通信技术的应用，同时介绍了在系统中如何建立数据日志及监视进程活动。     

在SCOUNIX环境下开发实时通信系统

在SCOUNIX环境下开发实时系统 ,不仅可以利用UNIX的多任务特性 ,建立起高效可靠的系统 ,而且软硬件成本较低 ,还能享有商业软件的技术服务。介绍了基于SCOUNIX环境开发实时通信系统时多路串行通信技术及UDP网络通信技术的应用 ,同时介绍了在系统中如何建立数据日志及监视进程活动     

移动监控终端无线传输系统的设计与实现

设计并实现了一个移动监控终端无线传输系统,该系统能够做到在不同的网络环境中实现监控终端定位信息的无线传输。结合定位终端定位信息的应用途径和当前网络环境日趋多样化的特点详细阐述了在不同网络环境中实现监控终端定位信息实时无线传输的重要性与必要性。在此基础上,较细致地说明了系统的工作原理,给出了系统结构框图,并介绍了系统各个模块的功能。实验证实,该系统可在基于IEEE802.11技术标准的WIFI无线网络和2代移动通信网络环境中实现监控终端定位信息的实时无线传输,并实现监控终端与控制中心之间简单的信息交互。     

建立WebGIS的月球三维可视化关键技术

嫦娥工程获得了大量月球探测数据。针对让公众用户通过网络获取月球信息,更好了解月球知识的需求,地面应用系统提出了建立基于WebGIS的月球三维可视化系统的解决方案。首先介绍了国内外三维月球的发展现状,详细分析了开发WebGIS系统的客户端和服务器端技术,重点阐述了月球空间数据模型和三维场景可视化渲染等三维GIS可视化关键技术,为建立我国的三维月球可视化系统提供了理论支持。     

网络技术在时间服务工作中的应用

主要介绍网络技术在授时中心守时实验室的守时及授时服务系统中的应用情况。守时系统是一种需要连续、可靠运转的复杂系统，包括守时钟组、比对测量系统、原子时归算等多个环节。原子时专用局域网是守时系统的一个重要的组成部分，它有效地提高了守时、原子时及相关数据资料的传递和交换速率。时间服务的网络化、自动化不仅有效提高了工作效率，减少了人工过多干预造成的误差，更重要的是可以提高守时系统的可靠性和合理性。章详细介绍原子时局域网络（ATLAN）系统和计算机网络授时系统的设计情况。     

瞬变源快速自动响应观测系统的研究与实现

天文瞬变源后随观测对于瞬变源证认具有重要的意义。瞬变源发生的偶然性和光变的快速性要求后随观测系统具有快速自动响应的能力。介绍了基于Python开发的天文瞬变源快速自动响应观测系统的研究和实现,核心是基于Django架构实现数据库交互与模块调度功能。系统有基于VOEvent的警报消息传递、网络端状态监控与交互平台、数据自动处理和结果自动反馈以及望远镜控制接口等主要功能。通过在北京的中法天文卫星科学中心和兴隆观测基地之间的消息数据传递和实际触发观测测试表明,系统能满足中法天文卫星项目地基观测系统瞬变源后随自动响应观测的基本要求,同时系统还具有良好的可移植性,适用于其他类似的自动响应观测系统。     

Precipitable water vapor (PWV) estimations from the site of the Eastern Anatolia Observatory<Superscript>∗</Superscript> (DAG), a new astronomical observatory in Turkey

We present preliminary statistics on the precipitable water vapor (PWV) content over the Karakaya Hills in Erzurum city, where the largest optical and near-infrared astronomical telescope in Turkey will be operated. Since the observatory will observe in the near-infrared (NIR), it is intended to perform PWV measurements of the atmosphere above the site by using signal delays in Global Positioning System (GPS) communication. The analysis of the GPS data recorded on the summit for almost one year shows that the atmosphere over the site of the observatory, which has an altitude of 3170 m, has favorable conditions for NIR observations. From GPS measurements, we report that the site had an average PWV of 3.2 mm and a median PWV of 2.7 mm between October 6, 2016, and June 15, 2017. We also present the time dependency of the PWV content and the correlations between the amount of PWV and the other meteorological records gathered from radiosonde flights and ground-based measurements.     

Description of atmospheric conditions at the Pierre Auger Observatory using the Global Data Assimilation System (GDAS)

Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malargüe and averaged monthly models, the utility of the GDAS data is shown.     

A general observatory control software framework design for existing small and mid-size telescopes

A general framework for observatory control software would help to improve the efficiency of observation and operation of telescopes, and would also be advantageous for remote and joint observations. We describe a general framework for observatory control software, which considers principles of flexibility and inheritance to meet the expectations from observers and technical personnel. This framework includes observation scheduling, device control and data storage. The design is based on a finite state machine that controls the whole process.     

The Caltech solar site survey, 1965–1967

We describe the Caltech solar site survey in 1965–1967 directed by R. B. Leighton. The solar seeing at 102 locations in 34 sites in Southern California was evaluated by 6009 visual estimates with portable telescopes. Cloud cover and other meteorological factors were also measured, and sunlight recorders were operated at several sites. We have reanalyzed much of the data to determine its consistency and learn what else we could about the sites. The visual estimates show good internal consistency and correlation with photographic data.The seeing was found to be best at various sites associated with water, and we point out the importance of the Bowen ratio in determining the influence of water vapor on seeing. It was found that seeing at the different sites was not well correlated in time.The seeing was found to be best at Lake Elsinore, an inland sink. Good seeing was also found on the Caltech campus and at Big Bear Lake in the San Bernardino Mountains. Taking into account the better sky transparency and the feasibility of constructing an observatory in the lake, we chose Big Bear Lake for the site of a new observatory. The lack of correlation of seeing with transparency suggests the benefits of several smaller telescopes, targeted at specific goals, located at sites chosen for those goals.     

2.4m望远镜曝光时间计算器的设计和实现

望远镜的曝光时间计算器对于远程观测以及不熟悉整个观测系统的观测人员尤为重要,因为它可以帮助观测者制定合理的观测计划。设计并实现了高美古2.4m望远镜系统的曝光时间计算器(exposuretimecalculator,ETC),它可以根据望远镜及其终端设备的参数,通过计算给出待测天体曝光时间的参考值。这为观测者了解现有条件下极限观测能力,设置曝光时间或者是给定星等和曝光时间计算信噪比提供了依据。将ETC计算结果与实际测光标准星的数据进行了比较,结果表明ETC对测光标准星的计算结果是可靠的。     

山东大学威海天文台视宁度研究

山东大学威海天文台拥有口径1 m的赤道式反射光学望远镜,于2007年6月建成并投入使用。对天文台2008年、2009年的所有观测数据用编写的IRAF自动处理程序进行处理得到了大气视宁度值,对得到的大气视宁度进行了分析研究,并与天文台气象站获得的气象数据一起进行了分析。经分析得到了山东大学威海天文台的大气视宁度状况,同时得到了一些大气视宁度随气象因素变化的规律。     

A site evaluation campaign for a ground based atmospheric Cherenkov telescope in Romania

Around the world, several scientific projects share the interest of a global network of small Cherenkov telescopes for monitoring observations of the brightest blazars??the DWARF network. A small, ground based, imaging atmospheric Cherenkov telescope of last generation is intended to be installed and operated in Romania as a component of the DWARF network. To prepare the construction of the observatory, two support projects have been initiated. Within the framework of these projects, we have assessed a number of possible sites where to settle the observatory. In this paper we submit a brief report on the general characteristics of the best four sites selected after the local infrastructure, the nearby facilities and the social impact criteria have been applied.