共查询到20条相似文献，搜索用时 15 毫秒
1.
V. P. Aleshin E. A. Grishin O. A. Ivlev D. D. Novgorodtsev V. D. Shargorodsky 《Kinematics and Physics of Celestial Bodies》2016,32(5):255-259
Telescopes with aperture higher than 3 m and with travel rate of optical axis of more than 4 angular degrees per second are examined. These telescopes are used for estimating the situation in near-Earth space. Up to now, there are three telescopes with such parameters: SOR, AMOS, SST (all in the United States). A telescope of the same class with aperture of 3.12 m (information telescope TI-3.12) is under completion at Altai Optical Laser Center. The main technical performances of the TI-3.12 telescope are described in the paper. Current problems are defined and ways for their solution are presented. 相似文献
2.
G. Wolfschmidt 《Astronomische Nachrichten》2009,330(6):555-561
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) 相似文献
3.
8~10m级光学／红外望远镜的高分辨率光谱仪 总被引：1，自引：0，他引：1
介绍并比较了KeckSubaruVLTHET及Gemini中的5架8～10m天文望远镜的高分辨率光谱仪,分析这些仪器与2～4m级望远镜的阶梯光栅光谱仪或Coude光谱仪相比所采用的新设计思想和新技术. 相似文献
4.
Martin Nekola René Hudec Martin Jelínek Matůš Kocka Petr Kubánek Filip Münz Cyril Polášek Vojtěch Šimon Jan Štrobl 《Experimental Astronomy》2010,28(1):79-85
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. 相似文献
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J. C. Bhattacharyya 《Astrophysics and Space Science》1986,118(1-2):45-49
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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. 相似文献
8.
针对太赫兹波段天文点源目标较少, 指向测量相对困难的特点, 研究了利用与太赫兹天线共轴的小型光学望远镜来辅助太赫兹望远镜指向测量以及建立指向误差修正模型的方法. 依托紫金山天文台1.2 m斜轴式太赫兹天线开展了光学辅助指向测量的实验研究, 利用一台安装在天线背架上的100mm口径折射式光学望远镜获得了优于2$''$的指向测量精度. 此外, 通过对斜轴天线的结构分析以及大气折射和本地恒星时(Local Sidereal Time, LST)偏差等误差来源的分析, 建立了包含23个误差项的斜轴式光学指向修正模型, 实现了约3$''$的拟合精度. 最后, 借助高精度数字摄影测量对光电轴一致性进行了标定, 并针对其对指向模型精度的影响进行了讨论. 研究成果将为南极5 m太赫兹望远镜(The 5m Dome A Terahertz Explorer, DATE5)及其他太赫兹望远镜提供指向测量和指向修正模型方面的技术参考. 相似文献
9.
We analyze the properties of high-resolution spectrographs fed from the telescope through optical fiber links. We report the
results of tests performed with the fiber-fed spectrograph that we developed for 1–2 m telescopes. 相似文献
10.
Jenkins 《Monthly notices of the Royal Astronomical Society》1998,294(1):69-92
Fast guiding may improve the images delivered by telescopes. It may be implemented fairly cheaply and offers an upgrade path to smaller telescopes, which will make them more useful in the 8-m era. However, the detailed performance of a fast guiding system must depend on many parameters and this makes it difficult to assess its precise scientific benefits. This paper provides a comprehensive mathematical framework for calculating the performance of fast guiding systems. A range of models has been calculated that illustrates the benefits for telescopes of various sizes in various wavelength ranges. Three measures of performance have been examined: FWHM, 50 per cent encircled energy diameter and energy concentration in a 0.35-arcsec aperture. Typical gains over natural seeing are found to be in the 20 to 40 per cent range at useful levels of sky coverage. Other things being equal, small telescopes do not benefit as much as large ones from fast guiding. The sensitivity of these benefits to assumptions has also been examined, and this highlights the need to operate in the correct wavelength range for the aperture in question. The largest perturbations to ideal models are likely to be the result of telescope windshake and the outer scale of turbulence. If there is appreciable windshake, fast guiding will yield larger benefits than expected from the natural seeing. A short outer scale (a few hundred metres) will, however, lose most of the gains. 相似文献
11.
Three types of prime focus correctors for Chinese 2.16m telescope are introduced in this paper. Each corrector has a 2 degree field and can be used to compensate the atmospheric dispersion of 6″. All the three correctors have excellent image quality and the angles between the principal rays and the optical axes are quite small. There is no special technological difficulty in their fabrication. These designs can not only be used in the 2.16m telescope but also be applied to other large telescopes. 相似文献
12.
H. Touma 《Astrophysics and Space Science》1997,258(1-2):47-53
The interest in a Rotating Slit-Aperture Telescope (RSAT) among other synthetic aperture telescopes is its capability of being
easily coupled with a spectrograph, in order to give reconstructed images of an astronomical object as a function of the light
wavelength. Each colored image is comparable with the others for fruitful astrophysical applications. The principle of image
reconstruction is well known: it consists of the inversion of the set of projections (Radon transform) given by the telescope
during its rotation around its optical axis. A full coverage of the two dimensional Fourier plane can be obtained by rotating
the SAT. This problem has led to intense developments for medical imaging (tomography). One of the main difficulties in the
reconstruction process in space may come from the jitter of the rotation axis of the RSAT. A set of projections uncorrected
for this jitter produces very fuzzy reconstructed images. An elegant solution to the necessary phasing between successive
projections is proposed which makes use of a small auxilliary telescope, and some numerical simulations are presented.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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James M. Cordes 《Experimental Astronomy》2009,26(1-3):79-94
The early days of radio astronomy showed incredibly diverse experimentation in ways to sample the electromagnetic spectrum at radio wavelengths. In addition to obtaining adequate sensitivity by building large collection areas, a primary goal also was to achieve sufficient angular resolution to localize radio sources for multi-wavelength identification. This led to many creative designs and the invention of aperture synthesis and VLBI. Some of the basic telescope types remain to the present day, now implemented across the entire radio spectrum from wavelengths of tens of meters to submillimeter wavelengths. In recent years, as always, there is still the drive for greater sensitivity but a primary goal is now to achieve very large fields of view to complement high resolution and frequency coverage, leading to a new phase of experimentation. This is the “back to the future” aspect of current research and development for next-generation radio telescopes. In this paper I summarize the scientific motivations for development of new technology and telescopes since about 1990 and going forward for the next decade and longer. Relevant elements include highly optimized telescope optics and feed antenna designs, innovative fabrication methods for large reflectors and dipole arrays, digital implementations, and hardware vs. software processing. The emphasis will be on meter and centimeter wavelength telescopes but I include a brief discussion of millimeter wavelengths to put the longer wavelength enterprises into perspective. I do not discuss submillimeter wavelengths because they are covered in other papers. 相似文献
16.
Lucia Sabbatini Francesco Cavaliere Giorgio Dall’Oglio Antonio Miriametro Licia Pizzo Dario Mancini Guido Torrioli 《Experimental Astronomy》2011,31(2-3):199-214
COCHISE (Cosmological Observations at Concordia with High-sensitivity Instrument for Source Extraction) is a 2.6 m telescope located on the high Antarctic Plateau near the Italian–French Concordia Base. The telescope is mainly devoted to Cosmological observations, able to operate between 200 μm and 3 mm of wavelength. In this paper we describe the main characteristics of the instrument. We also report on the first light, obtained during summer 2010–2011: this result marks the beginning of millimetre astrophysical observations at Concordia. Responsivity, noise equivalent temperature and field of view of the instrument are reported. At present COCHISE is the largest telescope located at Concordia. Beside the scientific expectations, the use of this kind of instrument in the Antarctic environment poses technological aspects of relevant interest: thus COCHISE can be considered as a pathfinder for future Antarctic telescopes. 相似文献
17.
ISLA will be an astronomical observatory, operating at the upper limit of our planet Earth atmosphere, offering space like
observing conditions in most aspects. ISLA can be maintained easily, modified easily if necessary, always kept at the state
of the art and operated for very extended periods without polluting the stratosphere. ISLA is ideally suited to become the
first world space observatory as the observing conditions are very much space-like – diffraction limited angular resolution,
very low ambient temperature, remote control – however ISLA is easily accessible, telescopes and instruments can be continuously
improved and ISLA's costs corresponds only to those of ground-based modern astronomical installations like the ESO-VLT-, KECK-
and GEMINI-observatories. The cost of observing and experimenting on ISLA will be orders of magnitudes lower than those of
building and operating any space telescope, allowing the astronomers of developing nations to participate in the ISLA observatory
within their limited financial possibilities as competent and full partners. ISLA's 4-m and 2-m telescopes will operate diffraction
limited from 0.3 μm in the optical, over the infrared, far-infrared to the sub-mm spectral range. ISLA's individual telescopes
will permit imaging with 20 milli-arcsec spatial resolution in the optical, 5 times better than the Hubble Space Telescope.
ISLA's telescopes can be combined to form an interferometer with a maximum baseline of 250 m with nearly complete coverage
of the u,v plane. Interferometric resolution will be of the order of 20 micro-arcsec for the optical. ISLA will thus offer
spatial resolution comparable or better than the intercontinental VLBI radio interferometers. ISLA's telescope efficiency
will be many orders of magnitude better than comparable ground-based telescopes. The light collecting power of ISLA's interferometric
telescopes will be orders of magnitudes greater than the future space interferometers under discussion. ISLA, being an aviation
project and not a space project, can be realised in the typical time scale for the development of aviation: about 5 years.
ISLA's cost for the whole observatory, including its movable ground station etc. will be of the order of a typical medium
size ESA space mission. ISLA's lifetime will be in excess of many decades, as it can easily be maintained, modernised, repaired
and improved. ISLA will become the origin of a new astronomical international organisation with worldwide participation. ISLA's
telescopes will be of the greatest importance to all astronomical fields, as it will permit to study much fainter, much more
distant objects with microscopic spatial resolution in wavelength regions inaccessible from ground. ISLA's many telescopes
permit easily simultaneous observations at many wavelengths for rapidly varying objects, from continuously monitoring the
surfaces of the planets in our solar system, surfaces of close-by stars, nuclei of galaxies to QSO's.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
KONG Xu LIN Lin LI Jin-rong ZHOU Xu ZOU Hu LI Hong-yu CHEN Fu-zhen DU Wei FAN Zhou MAO Ye-wei WANG Jing ZHU Yi-nan ZHOU Zhi-min 《Chinese Astronomy and Astrophysics》2014
In recent years the number of worldwide 8∼10 m-class ground-based telescopes is continually increased, the 4 m-diameter or smaller telescopes have become the small and medium-sized telescopes. In order to obtain some noticeable scientific results by using these existing small and medium-sized telescopes, we have to consider very carefully what we can do, and what we can not. For this reason, the Time Allocation Committee of the 2.16 m telescope of the National Astronomical observatories of China (NAOC) has decided to support some key projects since 2013. The long-term project “Spectroscopic Observations of the Star Formation Regions in Nearby Galaxies” proposed by us is one of three key projects, it is supported by the committee with 30 dark/grey nights in each of three years. 相似文献
19.
Peter Cogan 《Astrophysics and Space Science》2005,297(1-4):275-281
The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is the next-generation ground-based gamma-ray observatory
that is being built in southern Arizona by a collaboration of 10 institutions in Canada, Ireland, the UK and the USA. VERITAS
is designed to operate in the range from 50 GeV to 50 TeV with optimal sensitivity near 200 GeV; it will effectively overlap
with the next generation of space-based gamma-ray telescopes. The first phase of VERITAS, consisting of four telescopes of
12 m aperture, will be operational by the time of the GLAST launch in 2007. Eventually, the array will be expanded to include
the full array of seven telescopes on a filled hexagonal grid of side 80 m. A prototype VERITAS telescope with a reduced number
of mirrors and signal channels has been built. Its design and performance is described here. The prototype is scheduled to
be upgraded to a full 499 pixel camera with 350 mirrors during the autumn of 2004.
The VERITAS collaboration consists of universities and institutions from Ireland, UK, USA and Canada. See for a full listing. 相似文献
20.
We present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parameters including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies–Cotton (DC) and Schwarzchild–Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30–40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. We attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design. 相似文献