天文光学望远镜轴系驱动方式发展概述

该文首先介绍了已投入使用的2.5米口径以上的25架地平式光学望远镜和11架赤道式光学望远镜轴系驱动方式,并概述了天文光学望远镜轴系驱动及其相关技术的发展过程;然后对目前国际上在研的6架大型光学望远镜和预研的10架极大光学望远镜轴系所采用的驱动形式进行了归类;最后分析了未来极大光学望远镜轴系驱动的发展趋势和与之相关的研究内容.     

Robotic telescopes for high energy astrophysics in Ondřejov

We report on two small aperture robotic telescopes called BART and D50 operated in Ondřejov. Both telescopes are capable of automatic observation of gamma ray burst (GRB) optical afterglows. Coordinates of GRBs are taken from alerts distributed via Internet. Telescopes observe other interesting high energy sources when there is not any alert. The smaller telescope BART has aperture D = 254 mm. The bigger telescope D50 has a primary mirror of diameter D = 500 mm. Both telescopes are controlled by free software package RTS2 and are accessible through Internet. We describe the two telescopes and related software and show some results such as our first observed optical counterpart of GRB.     

Pointing of HAGAR telescope mirrors

An array of seven atmospheric Cherenkov telescopes was commissioned at a high altitude site in Hanle in the Ladakh region of the Himalayas. The array called HAGAR has been designed to observe celestial γ-rays of energy >100 GeV. Each telescope is altitude-azimuth mounted and carries seven parabolic mirrors whose optic axes are co-aligned with the telescope axis. The telescopes point and track a celestial source using a PC-based drive control system. Two important issues in positioning of each HAGAR telescope are pointing accuracy of telescope axis and co-alignment of mirrors’ optic axes with the telescope axis. We have adopted a three pronged strategy to address these issues, namely use of pointing models to improve pointing accuracy of the telescopes, RA-DEC scan technique to measure the pointing offsets of the mirrors and mechanical fine-tuning of off-axis mirrors by sighting a distant stationary light source. This paper discusses our efforts in this regard as well as the current status of pointing and monitoring of HAGAR telescopes.     

RTS2: Lessons learned from a widely distributed telescope network

RTS2 (Remote Telescope System 2) is a highly modular open source telescope and observatory management software package. It evolved from RTS, which was developed in Python to control a telescope aimed at observing optical transients of γ ray burts. The development of a network system capable of operating robotic telescopes is both difficult and complicated. Along with continued software development one must be concerned with maintaining operations and obtaining results. This is a review of experiences gained building a network of robotic telescopes. It focuses on describing which issues are important during development of the robotic observatory software and requirements for future development of the RTS2 package. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

射电天文中焦面阵或多波束馈源的应用

焦面阵技术或者多波束馈源系统已经日益广泛地应用于现代射电望远镜，因为它可以充分地利用同一射电望远镜反射面所能提供的信息，在观测比射电望远镜方向瓣大得多的展源时数倍乃至数十倍地提高观测的速度；当存在大气层或电离层的起伏或不均匀影响观测成像质量时，可消除这种影响，提高观测质量；利用焦面阵各单个馈源接收到的信息的互相关，则可以实时监控射电望远镜的反射面、二次反射面、指向精度，从而降低地面上大射电望远镜或空间射电望远镜的精度要求和造价。目前焦面阵已经愈来愈广泛地配置在毫米波射电望远镜和大型射电望远镜的主要波段。对此作了一个较新和全面的评述，对焦面阵应用中的限制，包括相位误差的限制和性能价格比的考虑和可能的前景作了简要的介绍。还分析了在计划中的大型主动球反射面射电望远镜（即FAST）上，配置焦面阵的相应限制、问题和难点，提出了初步的建议，并给出经中英双方讨论后初步拟定的FAST频段、波束及低噪声放大器的配置。     

Drive-Control System for the TACTIC Gamma-Ray Telescope

A PC-based drive-control system has been developed for the altitude-azimuth mounted TACTIC -ray telescope to control the speed and direction of motion of its 2-axes. Details of various hardware components chosen for the telescope, including hybrid-stepper motor, 16-bit absolute encoder and CAMAC-based programmable stepper motor controller, are discussed in this paper. The telescope-control strategy, based on the position-loop with a proportional type control for the source-seek mode and the on/off type control for the tracking mode, is explained in detail. Some important performance features of the telescope, including its blind-spot size, drive-system backlash and encoder-error compensation, are also presented. The drive system has been extensively field-tested and has been operating satisfactorily during observation campaigns carried out since March 1997 with the TACTIC Imaging Element. A tracking accuracy of ±3 arc-minutes has been achieved. A test report of its performance, with regard to its tracking accuracy on the basis of successful detection of TeV -rays from the active galaxy Markarian 501 in April–May 1997, is also presented.     

A Simple Model Of Software Costs For The Square Kilometre Array

Software costs for radio telescopes have nearly always been underestimated. Since the Square Kilometre Array is often called a software telescope, repeating the usual error would be particularly egregious. We estimate software costs by scaling from the reasonably well-known costs for the Atacama Large Millimeter Array. The resulting model has sharp dependency on the complexity of the SKA, suggesting the obvious – that software costs can most easily be limited by constraining the scientific and operational requirements. A bottom-up costing will not be possible until SKA is much more clearly defined. For the moment, we recommend that 20% of the SKA budget be allocated to software development.     

射电望远镜的发展和前景

在近代科学技术发展的基础上诞生和成长起来的射电天文学已经走过了66年的历程,作为射电天文学主要探测工具的射电望远镜有了长足的进步,面临21世纪人类社会和自然科学技术包括天文学发展的挑战,射电望远镜及射电天文学将迈出新的步伐．从射电天文学和射电望远镜发展的关系、射电望远镜几个主要发展方向和目前水平、自90年代以来逐步勾画而明确起来的未来发展方向等方面阐明了射电望远镜的发展和前景,以作为我国发展新一代射电望远镜的参考．     

一种液晶显示系统的单片机接口设计

液晶显示器（LCD）工作电压低、功耗小、能与CMOS电路匹配；且显示柔和、字迹清晰、重量轻、可靠性高、寿命长，自问世以来其发展速度之快，用途之广远远超过了其它发光器件。在自动化仪表及自动控制系统中，越来越多的设计者采用液晶显示与仪器对接，尽管其接口电路较传统的LED显示器复杂，由于其独特的优点，正得到广泛地应用。现介绍一种单片机LCD显示器接口的设计。在使用步进电机进行精密自动控制的系统中，利用8031单片机作为控制器，加之使用8255并行接口，可实现移位显示，也可适时显示转角信息和检测信息。该设计自动化程度高、可控性强，可用于天文仪器的精密定位、扫描以及其它自控监示系统。     

RTS2中新CCD类型扩展方法

CCD是天文望远镜中最常见的观测终端设备,也是望远镜自主控制系统中的重要组成部分。随着天文望远镜自主观测需求的不断出现以及技术的快速发展,开源的RTS2软件系统成为目前该领域研究中受到较多关注的系统之一。但RTS2支持的CCD设备较为有限,同时控制接口约定也相对固定。在针对部分特殊的CCD设备(如LAMOST中采用的32台CCD设备、选址用的部分CCD设备)时,仅实现原有类的方法是不够的。在深入分析RTS2源码的基础上,重点从参数、命令、协议扩展方面研究基于原有的Camera类,通过继承的方法构造新的CCD类型,实现对LAMOST项目的 CCD控制,取得了较好的效果,对在RTS2中集成望远镜系统其他类型设备也有较好的参考价值。     

LAMOST CCD camera-control system based on RTS2

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST) is the largest existing spectroscopic survey telescope, having 32 scientific charge-coupled-device(CCD) cameras for acquiring spectra. Stability and automation of the camera-control software are essential, but cannot be provided by the existing system. The Remote Telescope System 2 nd Version(RTS2) is an open-source and automatic observatory-control system. However, all previous RTS2 applications were developed for small telescopes. This paper focuses on implementation of an RTS2-based camera-control system for the 32 CCDs of LAMOST. A virtual camera module inherited from the RTS2 camera module is built as a device component working on the RTS2 framework. To improve the controllability and robustness, a virtualized layer is designed using the master-slave software paradigm, and the virtual camera module is mapped to the 32 real cameras of LAMOST. The new system is deployed in the actual environment and experimentally tested. Finally, multiple observations are conducted using this new RTS2-frameworkbased control system. The new camera-control system is found to satisfy the requirements for automatic camera control in LAMOST. This is the first time that RTS2 has been applied to a large telescope, and provides a referential solution for full RTS2 introduction to the LAMOST observatory control system.     

Considerations for the next generation of solar telescopes: A systems approach to solar physics

The exciting new high resolution images from the one meter Sunrise balloon telescope and the first images from the 1.6 meter Big Bear telescope together with the continuing data from the 1 meter Swedish Solar Observatory demonstrate the promise of the new generation of multimeter solar telescopes. While the promise of the new generation of telescopes is great the technical challenges to build them will require the efforts of a significant fraction of the solar community. In this talk I will emphasize the need for an integrated systems approach to the development of the telescope, its instruments, its software, and its operations and management structures. The experience of several decades of space mission has taught us a great deal about the value of planning mission development from the definition of the primary scientific objectives to the delivery of the data to the science community. Much of these lessons learned, often painfully, should provide guidance to those in developing the new telescope systems (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A simulation model for a telescope earthquake analysis: the VST primary mirror safety system

The VST (VLT Survey Telescope) is a wide field survey telescope going to be commissioned at Cerro Paranal (Chile). Due to the geological nature of the area, telescopes in Chile can be submitted to unpredictable and sometimes severe earthquake conditions. The commonly used response spectrum analysis has proven to be not suitable to evaluate the behavior of the VST telescope during an earthquake, due to the high number of devices with a nonlinear force–displacement characteristic in the primary mirror cell. Therefore, a nonlinear transient analysis based on a mixed Finite Element-Simulink approach has been carried out. A linear Finite Element (FE) model of the telescope has been developed and exported to Simulink, using a space state model representation. Then all nonlinear devices have been properly modeled and artificial accelerograms based on seismic history of the site have been applied. The paper focuses on the Simulink model, while giving an overview of the whole procedure.     

Study of central control system for FAST

FAST(The Five-Hundred-Meter Aperture Spherical Radio Telescope) is an under-building radio telescope which will be the largest single dish in the world. Through the study of the central control system, in accordance with the actual operation of the telescope and observation process, this article introduces the physical models for engineers and observers, the central control system architecture design, basic support modules and the necessary interfaces. We simulated observation control process and telescopes monitoring and control process, and took Active Reflector System as a subsystem example to complete the control system design and implementation using EPICS (Experimental Physics and Industrial Control System). The Central control system, with active reflector systems, feed supporting system has been taken to an integration test at Miyun model. In the case of the normal operation of the various sub-systems of the Miyun model by the central control system, a coordinated control is achieved.     

Automatic guide for the Raduga astronomical spectrograph

An automatic mirror guide has been designed and made for the Raduga fiber-optic echelle spectrograph. The new device was built into one of the parts of the spectrograph and allows the work of observers to be facilitated significantly. The automatic guide efficiently removes stellar image oscillations at frequencies of 0–2 Hz, which compensates almost completely for errors in setting the polar axis of a telescope and in its clockwork drive. The guide can be used on any telescope with a focal length of more than 5 m and has operated on two different telescopes. Over two observing seasons, several hundred stellar spectra were taken with the Raduga spectrograph using the automatic guide.     

北京天文台的WET三通道高速光度计

对北京天文台新近改造成的三通道高速光度计的结构和性能进行介绍,并给出了在兴隆站85公分望远镜的一些实测结果.     

The development of the Schmidt telescope

Bernhard Schmidt (1879–1935) was born in Estonia. After a few years of studying engineering he ran an optical workshop in Mittweida, Saxonia, between 1901 and 1927. Astronomers appreciated the quality of his telescopes. Starting in 1925, on behalf of the Hamburg Observatory, he developed a short focal length optical system with a large field of view. For this purpose, Schmidt moved his workshop to the observatory. He succeeded in inventing the “Schmidt telescope” which allows the imaging of a large field of the sky without any distortions. Schmidt's first telescope (spherical mirror diameter 0.44 m, correction plate 0.36 m diameter, aperture ratio 1:1.75, and focal length 0.625 m) has been used since 1962 at the Boyden Observatory in Bloemfontein/South Africa. Apart from his 0.36m telescope, Schmidt produced a second larger one of 0.60m aperture. Shortly after Schmidt's death, the director of the observatory published details on the invention and production of the Schmidt telescope. After World War II, Schmidt telescopes have been widely used. The first large Schmidt telescope, the “Big Schmidt” (1.26 m), Mount Palomar, USA, was completed in 1948. The 0.80 m Schmidt telescope of Hamburg Observatory, planned since 1936, finished in 1954, is now on Calar Alto/Spain (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Toward high spatial resolution in solar observations

To achieve high spatial resolution capability for IR solar observations, we suggest the use of a special mask placed before the entrance aperture of large conventional optical telescopes. Such a mask would match well the resolution of a non-redundant array and would provide safe operation of a large telescope used for solar observations. The proposed solution has the additional advantage of relatively low cost because already-existing optical telescopes are used.     

Autonomous software: Myth or magic?

We discuss work by the eSTAR project which demonstrates a fully closed loop autonomous system for the follow up of possible micro‐lensing anomalies. Not only are the initial micro‐lensing detections followed up in real time, but ongoing events are prioritised and continually monitored, with the returned data being analysed automatically. If the “smart software” running the observing campaign detects a planet‐like anomaly, further follow‐up will be scheduled autonomously and other telescopes and telescope networks alerted to the possible planetary detection.We further discuss the implications of this, and how such projects can be used to build more general autonomous observing and control systems. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)