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。     

基于WebSocket的RTS2 Web控制研究

望远镜自主观测软件是自主控制天文望远镜技术中的重要组成部分,也是当前天文技术研究的一个热点。开源的RTS2是目前非常流行的望远镜自主观测的软件系统,但RTS2中提供的Web控制仅是一个演示,功能相对简单,也不具备实时性。随着HTML5和WebSocket技术的发展,在深入分析RTS2源码的基础上,实现了RTS2服务器端的WebSocket支持,利用HTML5的WebSocket技术完成了一个望远镜实时监控Web终端系统原型,为远程控制与状态实时监控提供了一个简单、方便的平台,为后续研究工作打下了良好的基础。     

天文CMOS相机测试平台及控制系统的实现

CMOS相机是一种重要的固体成像设备?随着科研级CMOS相机的性能不断提高,现已广泛应用于科研领域?新真空太阳望远镜的成像设备也使用CMOS相机?因此建立一个天文CMOS相机测试系统?对于新购CMOS相机的验收以及现有CMOS相机的定期检测和维护有十分重要的意义。介绍了CMOS相机测试平台的硬件组成,并针对实际测试中对设备控制的需求,以及利用控制器对相应的设备直接控制,提出了基于TCP/IP协议以及串口通信的设计方案?利用C#编程语言设计了一套多线程并行的控制系统软件?实现各设备在局域网内的远程并行控制。通过对设备的运行测试,结果表明,系统能良好地控制各设备的正常运行?满足测试系统集成控制的需求.     

丽江2.4米望远镜多波段测光观测控制系统的设计与开发

丽江2.4 m望远镜在卡塞格林焦点上安装多个观测设备,为了最大限度地提高望远镜的观测效率,需要实现对各终端控制系统的集成控制。原有的多波段测光系统的控制程序不具备集成化的条件,需要对其进行集成化开发以满足要求。借鉴云南暗弱天体光谱成像仪和望远镜的控制系统,在Linux系统下对多波段测光系统的控制系统进行重新开发,设计并完成了3个主要部分:观测控制程序、设备控制程序和设备数据库,成功实现了多波段测光系统、云南暗弱天体光谱成像仪与望远镜统一的控制模式,使其具备与其它设备控制系统集成的能力,满足多终端集成控制的要求。     

一种基于异构操作系统的RTS2CCD相机扩展方法

RTS2作为远程望远镜控制的开源框架,在天文自主观测领域得到了广泛的应用,在观测仪器中,CCD是天文望远镜系统中一个必不可少的组成部分。在实际工作环境中,部分CCD在Linux操作系统下缺乏支持,致使该设备无法在RTS2框架中协同工作,在无替代CCD的情况下导致整个望远镜系统无法正常使用。借助Windows下的Direct Show技术对视频设备的支持,在Linux与Windows异构操作系统间利用Socket通信技术建立访问控制桥梁,从而扩展出一种新的CCD类型。通过测试,RTS2能借助该设备控制Windows下的CCD,并实时获取图像,研究取得了一定的成果:(1)使用Direct Show技术控制和访问Windows驱动模型(Windows Driver Model,WDM)的所有CCD获得一种通用的CCD访问方式;(2)借助Socket通信进行延伸对RTS2框架下的其他类型设备在异构操作系统下扩展具有参考意义。     

多功能天文经纬仪图像采集系统

多功能天文经纬仪是云南天文台新近研制的一种基于通用CCD观测的天体测量望远镜。在这台新型望远镜中,用两个模拟相机分别测量仪器的水平差和高度轴的准直差。当望远镜工作时,望远镜控制系统发出两路触发信号．一路控制数字相机,另一路控制两个模拟相机。两个采集卡分别安装在不同的工作站上,工作在外触发模式。介绍了望远镜的转轴观测模式,主要包含转轴前和转轴后两个观测阶段,采集图像的时刻和数量是由外触发信号控制的。介绍了硬件结构图。说明了软件编写的流程和实现方法．并且对系统中涉及的主要程序算法进行了较为详细的说明。图像采集软件的编写采用VC＋＋和SaperaLT。给出了采集系统软件的工作界面及图像采集系统采集的图像．并对数字相机拍摄的恒星像进行了简单的分析。     

10赫兹漫反射激光测距控制系统的设计与实现

设计和实现了云南天文台1．2m望远镜10Hz共光路漫反射激光测距控制系统,包括激光器、信号探测器和测时设备等的控制。并将系统应用于实际观测中,使用结果表明系统运行正常,且已成功实现了部分空间碎片的漫反射激光测距。将测时设备换为事件计时器后,该系统可直接用于激光测月试验。     

近地天体望远镜的控制软件系统

配合CCD相机更新,2013年近地天体望远镜(CNEOST,China Near Earth Object Survey Telescope)对硬件系统进行了改造,在此基础上重新设计并实现了控制软件系统,软件采用了基于Web Socket协议的消息机制,具有良好的扩展性;基于Web的用户界面,实现了近地天体望远镜在不同用户终端下的远程观测.自投入使用以来,系统运行稳定,大幅度提高了设备运行效率,降低了操作复杂度;同时也为未来类似的望远镜或望远镜云的系统设计提供了一次有益尝试.     

怀柔太阳观测基地三通道太阳望远镜局域网内远程观测终端系统设计

利用怀柔三通道太阳磁场望远镜对太阳进行多层次同步观测可以同时获得日面不同层次的活动图像,这对于更好的理解太阳物理有着重要意义.本文基于怀柔三通道太阳磁场望远镜开发了在局域网内能够对三通道CCD进行同步观测的远程终端观测系统,并通过此系统实现了怀柔基地三通道望远镜和小磁场望远镜的协同观测.系统设计采用vc.net集成开发环境,使用TCP/IP协议,通过套接字网络编程,对三通道太阳望远镜的三个CCD进行同步远程控制,目前系统已经在局域网内实现了图像数据和相机控制命令的传输等远程观测功能,大大降低了观测成本,并取得了初步的观测结果.     

一米新真空太阳望远镜光谱扫描观测系统设计

1 m新真空太阳望远镜(New Vacuum Solar Telescope,NVST)是国内用于对太阳进行观测和研究的大型科研设备,针对太阳活动区光谱观测的需求,在现有的大色散光谱仪及多波段光谱仪基础上,设计了光谱扫描设备,并基于C#设计了一套观测控制系统软件,实现扫描设备的运动控制和观测数据的采集。进行光谱扫描观测时,计算机控制扫描设备步进运动,并利用图像采集卡通过Camera Link总线采集CCD/CMOS相机的探测数据,基于多线程技术采集观测数据,将采集的图像数据存储成FITS(Flexible Image Transport System)文件,并将光谱图像数据处理成灰度图像用于软件界面监视。此套软件已用于1 m太阳望远镜光谱扫描观测,测试结果满足预期功能需求,为后续观测系统功能升级提供了良好的扩展性。     

Instructions for authors

正Research in Astronomy and Astrophysics publishes original research papers and reviews on all branches of astronomy and astrophysics.Reviews are by invitation only.Important new results that require rapid publication can be submitted as a Letter(Letters must be restricted in length to 6 printed pages).Authors who submit a paper are expected to be able to certify that the paper is original work,     

Research in Astronomy and Astrophysics CONTENTS

正~~     

Instructions for authors

正Research in Astronomy and Astrophysics publishes original research papers and reviews 011 all liranchcs of astronoiriy and astrophysics.Reviews arc by invitation only.Important new results that require rapid publication can be submitted as a Letter(Letters must be restricted in length     

Alkali and halogen chemistry in volcanic gases on Io

We use chemical equilibrium calculations to model the speciation of alkalis and halogens in volcanic gases emitted on Io. The calculations cover wide temperature (500-2000 K) and pressure (10⁻⁶ to 10⁺¹ bars) ranges, which overlap the nominal conditions at Pele (T=1760 K, P=0.01 bars). About 230 compounds of 11 elements (O, S, Li, Na, K, Rb, Cs, F, Cl, Br, I) are considered. The elemental abundances for O, S, Na, K, and Cl are based upon observations. CI chondritic elemental abundances relative to sulfur are used for the other alkalis and halogens (as yet unobserved on Io). We predict the major alkali species in Pele-like volcanic gases and the percentage distribution of each alkali are LiCl (73%), LiF (27%); NaCl (81%), Na (16%), NaF (3%); KCl (91%), K (5%), KF (4%); RbCl (93%), Rb (4%), RbF (3%); CsCl (92%), CsF (6%), Cs (2%). Likewise the major halogen species and the percentage distribution of each halogen are NaF (88%), KF (10%), LiF (2%); NaCl (89%), KCl (11%); NaBr (89%), KBr (10%), Br (1%); NaI (61%), I (30%), KI (9%). We predict the major halogen condensates and their condensation temperatures at P=0.01 bar are NaF (1115 K), LiF (970 K); NaCl (1050 K), KCl (950 K); KBr (750 K), RbBr (730 K), CsBr (645 K); and solid I₂ (200 K). We also model disequilibrium chemistry of the alkalis and halogens in the volcanic plume. Based on this work and our prior modeling for Na, K, and Cl in a volcanic plume, we predict the major loss processes for the alkali halide gases are photolysis and/or condensation onto grains. Their estimated photochemical lifetimes range from a few minutes for alkali iodides to a few hours for alkali fluorides. Condensation is apparently the only loss process for elemental iodine. On the basis of elemental abundances and photochemical lifetimes, we recommend searching for gaseous KCl, NaF, LiF, LiCl, RbF, RbCl, CsF, and CsCl around volcanic vents during eruptions. Based on abundance considerations and observations of brown dwarfs we also recommend a search of Io's extended atmosphere and the Io plasma torus for neutral and ionized Li, Cs, Rb, and F.     

Study on the Stressed Mirror Polishing with a Continuous Polishing Machine for Large Aperture Off-axis Aspheric Mirrors

A special stressed annular polishing technique is proposed to mill the off-axis aspheric sub-mirrors of a large segmented mirror with an annular polishing machine. Based on the basic principle of stressed annular polishing technique, a set of special stressing mechanisms are designed to convert milling the aspheric surfaces of sub-mirrors with different off-axis distances into milling the spherical surfaces with identical radii of curvature, so that they can be pol- ished simultaneously on a continuous polishing machine. It took about contin- uous 40 hours to polish a scaled-down mirror of the planning Chinese Future Giant Telescope (CFGT) using this technique. This mirror has the 330 mm di- ameter, 3.6 m off-axis distance, and the 21.6 m radius of curvature, and its max- imum asphericity is 16 micron. The experiment shows that this method has a high effciency, suits batch manufacturing, especially the batch manufacturing of aspheric sub-mirrors of the segmented primary mirror of an extremely large aperture telescope.     

The climatic and physiographic controls of the eastern Mediterranean over the late Pleistocene climates in the southern Levant and its neighboring deserts

Modern-day synoptic-scale eastern Mediterranean climatology provides a useful context to synthesize the diverse late Pleistocene (60–12 ka) paleohydrologic and paleoenvironmental indicators of past climatic conditions in the Levant and the deserts to its south and east. We first critically evaluate, extract, and summarize paleoenvironmental and paleohydrologic records. Then, we propose a framework of eastern Mediterranean atmospheric circulation features interacting with the morphology and location of the southeast Mediterranean coast. Together they strongly control the spatial distribution of rainfall and wind pattern. This cyclone–physiography interaction enforces the observed rainfall patterns by hampering rainfall generation south and southeast of the latitude of the north Sinai coast, currently at 31°15′.The proposed framework explains the much-increased rains in Lebanon and northern Israel and Jordan as deduced from pollen, rise and maintenance of Lake Lisan, and speleothem formation in areas currently arid and semiarid. The proposed framework also accounts for the southward and eastward transition into semiarid, arid, and hyperarid deserts as expressed in thick loess accumulation at the deserts' margins, dune migration from west to east in the Sinai and the western Negev, and the formation of hyperarid (< 80 mm yr^− 1) gypsic–salic soils in the southern Negev and Sinai. Our climatic synthesis explains the hyperarid condition in the southern Negev, located only 200–250 km south of the much-increased rains in the north, probably reflecting a steeper rainfall gradient than the present-day gradient from the wetter Levant into its bordering southern and eastern deserts.At present, the rainiest winter seasons in Lebanon and northern and central Israel are associated with more frequent (+ 20%), deeper Cyprus Lows traversing the eastern Mediterranean at approximately the latitude of southern Turkey. Even these wettest years in northern Israel do not yield above average annual rainfall amounts in the hyperarid southern Negev. This region is mainly influenced by the Active Red Sea Troughs that produce only localized rains. The eastern Mediterranean Cyprus Lows also produce more dust storms and transport higher amounts of suspended dust to the loess area than any other atmospheric pattern. Concurrent rainfall and dust are essential to the late Pleistocene formation of the elongated thick loess zone along the desert northern margin. Even with existing dust storms, the lack of rain and very sparse vegetation account for the absence of late Pleistocene loess sequences from the southern Negev and the formation of hyperarid soils.When the north Sinai coast shifted 30–70 km northwest due to last glacial global sea level lowering, the newly exposed coastal areas supplied the sand and dust to these active eastern Mediterranean cyclones. This enforced the latitude of the northern boundary of the loess zone to be directly due east of the LGM shoreline. This shift of coast to the northwest inhibited rainfall in the southern Levant deserts and maintained their hyperaridity. Concurrently, frequent deep eastern Mediterranean Cyprus Lows were funneled along the northern Mediterranean increasing (probably doubling) the rains in central and northern Israel, Lebanon, southwestern Syria and northern Jordan. These storms and rains formed lakes, forests, and speleothems only a short distance north of the deserts in the southern Levant.     

Active hot star shells

Interferometry in the visible provides milliarcsecond spatial resolution and thus has been used for studying the circumstellar environment of active hot stars. In this paper I will illustrate how the visibility modulus and phase can be used to better constrain the physics of Be disks through results from the VLA, the MkII and the GI2T interferometers. I will insist on the importance and the potential of coupling high angular resolution with high spectral resolution to the study of Be shells. Finally I will present a possible study of the circumstellar disk of Be stars using the VLTI. This revised version was published online in July 2006 with corrections to the Cover Date.     

Fitting X-ray Afterglow Light curves of Gamma-ray Bursts by Using the Magnetar Energy Injection Model

The central compact object for some gamma-ray bursts (GRBs) may be a strongly magnetized millisecond pulsar. It can inject energy to the outer shock of the GRB by through the magnetic dipole radiation, and therefore causes the shallow decay of the early afterglow. Recently, from a large number of GRB X-ray afterglows observed by Swift/XRT(X-ray telescope), it is revealed that many of them exhibit the shallow decay about 10²∼10⁴ s after the burst prompt emission. We have fitted the X-ray afterglow light curves of 11 GRBs by using the energy injection model of a magnetar with the rotation period in the millisecond order of magnitude. The obtained result shows the validity and universality of the magnetar energy injection model in explaining the shallow decay of afterglows, and simultaneously provides some constraints on the magnetic field strength and rotation period of the central magnetar.     

我国新一代VLBI数字基带转换器研制进展

数字化是目前设备研制发展的趋势,介绍了中国科学院上海天文台利用超大规模集成电路结合软件无线电技术,自主研发的我国新一代VLBI数字基带转换器(Chinese Data Acquisition System,简称CDAS).文中描述了设备的工作原理及其组成,并以VLBI观测实验数据证明其可行性.与原有的模拟设备(Anal...