Cassegrain Telescopes - an overview | ScienceDirect Topics
Physics and Astronomy. Cassegrain Telescopes are two-mirror telescopes with a corrector plate that helps to correct spherical aberration and allows for the elimination of other aberrations, providing a wide field of view. AI generated definition based on: Astronomical Optics (Second Edition), 2000. About this page.
Non-uniform temperature field measurement and simulation of a …
Jan 25, 2017 · The 3-m-aperture fully steerable telescope model is a ring-focus antenna with dual reflectors. It consists of the main reflector, subflector and turning unit. The main reflector is a rotating parabolic surface composed of an aluminum plate with a thickness of 1 mm with acrylic white paint on the surface. The subreflector is a rotating ...
Reflecting Telescope - an overview | ScienceDirect Topics
Jan 24, 1986 · The VISTA (Visible and Infrared Survey Telescope for Astronomy) is a wide-field reflecting telescope with a 4.1-m mirror, located at the Paranal Observatory in Chile. It is operated by the European Southern Observatory and started science operations in December 2009. VISTA is a survey telescope working at infrared wavelengths, and is one of the ...
Polarization comparison between on-axis and off-axis dual …
Dec 1, 2003 · The cross-polarization performance for an off-axis dual reflector telescope is shown to be equivalent to an on-axis telescope when used for a large-format focal plane array. The need for low sidelobes forces the on-axis designs to high curvature, which in turn leads to high cross-polarization at the edge of the field.
Parabolic Reflector - an overview | ScienceDirect Topics
Parabolic Reflector. In subject area: Computer Science. A parabolic reflector is a type of antenna that uses a curved surface to radiate or concentrate energy in parallel rays. It can be used for transmitting a focused beam of energy towards a target …
A novel design for giant radio telescopes with an active spherical …
Jul 1, 1998 · Abstract. A novel design for giant radio telescopes is proposed. Instead of using a complex feed system for the correction of spherical aberration (such as the Arecibo 3-reflector system), we propose to use an active main spherical reflector. The part of the main reflector illuminated by the feed is continually adjusted in real-time to fit as ...
Non-uniform temperature field measurement and simulation of a …
Jan 25, 2017 · The typical radio telescope structure is shown in Fig. 1 and mainly consists of four parts: the subreflector and quadripod, the main reflector and back-up structure, the elevation wheel and the azimuth bearing. The main reflector, back-up structure and elevation wheel, connected with the azimuth bearing by the horizontal pitch axis, can often ...
A way to improve the field of view of large aperture radio telescopes
Jul 1, 2005 · Abstract. There is a limitation on the field of view (FOV) of a large aperture radio telescope: the FOV decreases with increasing resolution and sensitivity of the telescope and the greater the aperture, the smaller the FOV. In order to enlarge the FOV, we may place several discrete feeds on the focal plane of the telescope.
A new mirror alignment system for the VERITAS telescopes
Jan 1, 2010 · Method and apparatus. Our alignment system uses a digital camera which is mounted at the centre of the telescope’s focal plane, facing the reflector. Images of the reflector are acquired at each point of a raster scan that the telescope performs centred on a bright star at a typical observing elevation.
Effect of the rail unevenness on the pointing accuracy of large …
Mar 1, 2017 · Then, a novel Reflector-Alidade Connecting Structure (RACS) scheme for large telescope is proposed based on these points. Finally, the new design scheme is applied to the numerical example of 110 m telescope, and the results verify the feasibility and effectiveness of the new scheme.
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