共查询到19条相似文献,搜索用时 203 毫秒
1.
2.
本文从望远镜及其光学系统、计算机软硬件、计时系统等方面介绍了澳大利亚Orroral激光测卫测月系统;并简单地介绍了以上各部分的特点。 相似文献
3.
4.
5.
网络技术在时间服务工作中的应用 总被引:1,自引:1,他引:0
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。 相似文献
6.
7.
邱育海 《中国科学院上海天文台年刊》1995,(16):280-281
本文描述了密云综合孔径射电望远镜的相加系统,以及该系统将被应用于行星际闪烁观测、脉冲星观测、一维太阳高速扫描和射电源定标等工作。 相似文献
8.
传统的哈勃星系形态分类法可以很好地对近邻的亮星系进行分类,但对低面亮度星系、矮椭球星系、矮旋涡星系以及高红移星系等都已无能为力。德沃古勒分类系统、叶凯士分类系统和范登伯分类系统是在哈勃分类法的基础上进行了发展和细化,利用光的中心聚集度或光度级等作为星系形态分类的参数。模型化分类系统试图定量地测量星系形态参数,但需要假定星系面亮度分布满足一定的形式,如r~(1/4)律、指数律等。最近几年,又有一些学者提出了非模型化分类系统,给出了若干个可以直接测量星系形态的结构参数,如:聚集度指数C、非对称指数A、簇聚指数S、基尼系数G及矩指数M_(20)。这些参数可以反映星系的形成历史、恒星形成、与其他星系的相互作用、已经发生或正在进行的并合活动等。它们不仅可以有效地给出近邻星系的分类特性,还能用于测量高红移星系的形态。该文介绍了不同的星系形态分类方法,比较了各类方法的优点和不足。在此基础上,最后介绍了基于非模型化分类系统的星系形态分类的研究进展。 相似文献
9.
本文介绍了VLBI记录系统在世界各主要台站的使用情况,对目前先进的VLBI记录系统的功能、记录格式等进行了比较和描述。 相似文献
10.
11.
一个巨型望远镜方案 总被引:4,自引:0,他引:4
提出一个有特色的巨型望远镜(FGT)方案.其主镜口径为30米,主焦比为1.2,由1095块圆环形子镜构成.采用地平式装置.光学系统包括Nasmyth系统、折轴(Coude)系统和一个大视场系统.提出一个由4个镜面组成的新的Nasmyth系统,在约10′的视场范围内像斑小于爱里斑,达到衍射极限.比传统的Nasmyth系统的衍射极限视场大得多.可在这样的大视场内同时作好几个小区域的衍射极限的观测.当由Nasmyth系统转换到折轴系统和大视场系统时,采用主动光学技术改变子镜的面形、倾斜和平移,产生一个新的主镜面形,使折轴系统和大视场系统都能得到很好的像质.大视场系统的视场直径25′,场曲轻微,并有可能校正大气色散.给出了子镜面形和位置的公差,并讨论了望远镜的装置和结构,方案中的特色和创新对未来大望远镜的研制有普遍意义. 相似文献
12.
G. Balmino 《Celestial Mechanics and Dynamical Astronomy》1974,10(4):423-436
The reference system defined by Veis and currently used for computing satellite orbits is not sufficiently accurate for some scientific applications, considering the new accuracy of laser data. We have therefore defined another orbital reference system with associated apparent forces. The reference system chosen is the mean celestial system 1970.0. The motion of a satellite is numerically integrated in the instantaneous celestial system (sideral system), taking into account all the complementary forces due to precession and nutation. The complete set of formulas is given here and has been introduced in a differential orbital improvement program. 相似文献
13.
14.
本文指出了子午环光栏自动控制系统研制的必要性,并简要介绍了控制原理.结果表明,该控制部分设计合理大大简便了操作. 相似文献
15.
《Chinese Astronomy and Astrophysics》2004,28(3):356-366
A configuration for the Future Giant Telescope is proposed. It is a 30m telescope with segmented primary mirror and alt-azimuth mounting. The aspherical f/1.2 primary mirror is made up of 1095 partial annular submirrors. The optical system includes a Nasmyth system, a coude system and a wide field system. The Nasmyth system has a novel design with four mirrors and provides a ∼10 arcmin field of diffraction-limited images, a much larger field than can be obtained by the traditional Nasmyth system. Several diffraction-limited observations each over a small field, can be carried out simultaneously. By applying active optics to change the shape, tip, tilt and piston of the submirrors, thereby to effect a new aspherical surface of the primary, excellent quality images can be obtained for the coude system and the wide field system. The wide field system has a field of 25 arcmin, the focal surface is only slightly curved and the atmospheric dispersion could be corrected. The tolerances of the surface shape and position for the submirrors, and the telescope mounting and structure are also discussed. The innovations in this configuration should have a general significance for future giant telescopes. 相似文献
16.
The system gain of two CCD systems in regular use at the Vainu Bappu Observatory, Kavalur, is determined at a few gain settings.
The procedure used for the determination of system gain and base-level noise is described in detail. The Photometrics CCD
system at the 1-m reflector uses a Thomson-CSF TH 7882 CDA chip coated for increased ultraviolet sensitivity. The gain is
programme-selected through the parameter ‘cgain’ varying between 0 and 4095 in steps of 1. The inverse system gain for this
system varies almost linearly from 27.7 electrons DN-1 at cgain = 0 to 1.5 electrons DN-1 at cgain = 500. The readout noise is ≲ 11 electrons at cgain = 66. The Astromed CCD system at 2.3-m Vainu Bappu Telescope
uses a GEC P8603 chip which is also coated for enhanced ultraviolet sensitivity. The amplifier gain is selected in discrete
steps using switches in the controller. The inverse system gain is 4.15 electrons DN-1 at the gain setting of 9.2, and the readout noise ∼ 8 electrons. 相似文献
17.
18.
A computer experiment on a one-dimensional self-gravitating system is described. We attempt to observe the dynamic time required for this system to thermalize by comparing the position and velocity densities with those predicted by the microcanonical ensemble. Hohl and Broaddus (1967) have previously reported an estimate of the thermalization time which is inferred from studies of the kinetic energy covariance. We ran the system for the time which they report and find that the system has not thermalized. Furthermore, there is no evidence that the system is even proceeding towards equilibrium in the time-scale considered here. Significant changes in the distribution do occur in a short time, after which the system remains in a stationary state which is not characteristic of equilibrium. 相似文献
19.
Yuan Tian Zheng Wang Jian Li Zi-Huang Cao Wei Dai Shou-Lin Wei Yong-Heng Zhao 《天文和天体物理学研究(英文版)》2018,(5)
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. 相似文献