Results 141 to 150 of about 714 (189)
Some of the next articles are maybe not open access.
ZERODUR for large segmented telescopes
SPIE Proceedings, 2003SCHOTT Glas manufactured more than 200 ZERODUR segments for various Telescopes: 84 pcs. 1.900 mm diameter × 76 mm menisci for Keck I and Keck II, 96 pcs. 1.180 mm hexagonal × 56 mm blanks for HET, 42 pcs. 1.870 mm hexagonal × 83 mm blanks for GTC, and produces at present, 40 pcs. 1.100 mm hexagonal × 82 mm blanks for LAMOST.
Hans F. Morian +3 more
openaire +1 more source
Piston phasing in segmented telescopes
SPIE Proceedings, 2016The next generation of optical telescope will provide a high-resolution imaging of celestial objects by using synthetic aperture. Measuring the piston error between the segments of the synthetic aperture becomes more and more important. We present a piston error detection method based on analyzing the intensity distribution of the image plane, which is
Junlun Jiang, Weirui Zhao, Baoyun Sun
openaire +1 more source
Measurement accuracy in control of segmented-mirror telescopes
Applied Optics, 2004Design concepts for future large optical telescopes have highly segmented primary mirrors, with the out-of-plane degrees of freedom actively controlled. We estimate the contribution to errors in controlling the primary mirror that results from sensor noise and, in particular, compare mechanical measurements of relative segment motion with optical wave ...
Douglas G, MacMartin, Gary, Chanan
openaire +2 more sources
Fabrication and alignment issues for segmented mirror telescopes
Applied Optics, 2004There is a great demand for new telescopes that use larger primary mirrors to collect more light. Because of the difficulty in the fabrication of mirrors larger than 8 m as a single piece, they must be made with numerous smaller segments. The segments must fit together to create the effect of a single mirror, which presents unique challenges for ...
Feenix Y, Pan +3 more
openaire +2 more sources
Diffraction effects from giant segmented-mirror telescopes
Applied Optics, 2003Ultrahigh contrast imaging with giant segmented-mirror telescopes will involve light levels of order 10(-6) times that of the central diffraction spike or less. At these levels it is important to quantify accurately various diffraction effects, including segmentation geometry, intersegment gaps, obscuration by the secondary mirror and its supports, and
Mitchell, Troy, Gary, Chanan
openaire +2 more sources
Giant segmented mirror telescope
Optical Fabrication and Testing, 2002AURA has answered the call of the astronomy decadal review committee for creation of a 30-meter Giant Segmented Mirror Telescope by forming a New Initiatives Office (NIO). One of the NIO activities in the past year has been to develop a GSMT point design as a tool that serves several purposes, including: exploring the dependence of scientific ...
Larry Stepp +4 more
openaire +1 more source
2012
12.1 Introduction Astronomers require larger and larger radiation-gathering apertures for their telescopes to penetrate farther into the mysteries of the universe. Large telescopes collect more photons and thus see fainter objects. These large apertures also increase the angular resolution across the object, as we saw in Chapter 10.
openaire +1 more source
12.1 Introduction Astronomers require larger and larger radiation-gathering apertures for their telescopes to penetrate farther into the mysteries of the universe. Large telescopes collect more photons and thus see fainter objects. These large apertures also increase the angular resolution across the object, as we saw in Chapter 10.
openaire +1 more source
Design of the segmented primary optical telescope
SPIE Proceedings, 2013Following with the “high-resolution upsurge” appeared in many counties in recent few years, it is an inevitable trend to increase the size of the Optical Telescope. However, because of the volume constrains of space-borne astronomical instruments, segmented reflector is thought as the main measure of future astro-physical missions by many scientists ...
Kaisheng Zhang +6 more
openaire +1 more source
Diffraction halo by a segmented telescope
SPIE Proceedings, 2008ABSTRACT We present an analytical description of the diffraction halo created by optical aberrations randomly distributed over hexagonal segments of a segmented mirror. We do not restrict ourselves to the piston and tip-tilt errors only, but show that the halo from any type of the aberration can be described in a general form. We also study the ability
openaire +1 more source
Phasing error detection for segmented telescopes
Optical Design and Testing VIII, 2018Higher angular resolution is required to telescope for scientific observing. Fabricating a large aperture monolithic mirror is limited by existing manufacturing technology, so segmented mirror has become a trend. But it also introduces the problem of co-phasing the segments to make the primary mirror be diffraction-limited.
Weirui Zhao, Dingding Yu
openaire +1 more source