Results 261 to 270 of about 15,556 (304)

Solar imaging with a segmented adaptive mirror

Applied Optics, 1992
A 19-segment adaptive-mirror system is currently being used on the Sacramento Peak 76-cm Tower Telescope to remove wave-front distortions resulting from atmospheric turbulence. The system has proven to be capable of substantially improving the quality of an image, at times achieving 0.33-arcsec resolution in visible wavelengths under 1-3-arcsec seeing ...
D S, Acton, R C, Smithson
openaire   +2 more sources

Segmented bimorph mirrors for adaptive optics: segment design and experiment

Applied Optics, 2014
We discuss the concept of lightweight segmented bimorph mirrors for adaptive optics. The segment consists of a monocrystal silicon substrate actuated by an array of in-plane piezoceramic (PZT) actuators with honeycomb electrodes. We focus on technological aspects of the segment design that are critical for space applications and describe a single ...
Bastaits, Renaud, Alaluf, David, Preumont, André, Horodinca, MIHAITA, Romanescu, Iulian, Burda, Ioan, Martic, Gregory, Rodrigues, Gonçalo   +7 more
openaire   +3 more sources

ASM: scaled down active segmented mirror developed to simulate a segmented primary mirror

SPIE Proceedings, 2006
The Active Segmented Mirror is a key subsystem of the Active Phasing Experiment. The size of the ASM is 154 mm in diameter. It will be used to test new types of phasing sensors recently developed within the ELT design study supported by the European Union.
Christophe Dupuy, Christoph Frank, Frédéric Gonté, Constanza Araujo Hauck, Roland Brast, Regina Esteves, Matti Nylund, Babak Sedghi, Frédéric Derie   +8 more
openaire   +1 more source

Edge-Control on Mirror Segments

International Optical Design Conference and Optical Fabrication and Testing, 2010
We outline requirements for mirror segment edges for extremely large telescopes, and introduce the new CNC machine for process verification. We review a promising approach for edge-control using the Precessions process, and report progress.
David Walker, Anthony Beaucamp, Guoyu Yu, Hongyu Li   +3 more
openaire   +1 more source

Giant segmented mirror telescope

Optical Fabrication and Testing, 2002
AURA 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, P.E. Gillett, S.E. Strom, M.K. Cho, G.Z. Angeli   +4 more
openaire   +1 more source

Algorithm for phasing a segmented mirror

SPIE Proceedings, 2004
This paper considers the problem of forming a preset surface of a segmented mirror of a telescope. An iteration algorithm based on analysis of the interference pattern of the radiation reflected from the mirror is used for phasing the mirror segments.
Feodor Y. Kanev, Vladimir P. Lukin, Nailya A. Makenova   +2 more
openaire   +1 more source

Segmented bimorph deformable mirror

Journal of Physics E: Scientific Instruments, 1989
The efficient low-voltage bending properties of PZT bimorph wafers have been combined with conventional microelectronics techniques to produce a 37-hex-faceted deformable mirror 23 mm in diameter and 1 mm thick. Despite the high ratio of diameter to thickness, at 633 nm an overall flatness of better than one-half wave peak-to-valley (PV) and one-tenth ...
F Forbes, F Roddier, G Poczulp, C Pinches, G Sweeny, R Dueck   +5 more
openaire   +1 more source

Mirror antenna with hexagonal segmentation

International Symposium on Antennas and Propagation Society, Merging Technologies for the 90's, 1990
The antenna designed for radiometer applications on the planned NASA Earth Science Geostationary Platforms is described. This antenna consists of two parts: a regular parabolic dish 5 m in diameter which converts the radiation from feeds into a collimated beam, and a movable mirror that redirects the beam to a prescribed scan direction.
B. Houshmand, S.W. Lee, M. Zimmerman, R. Acosta   +3 more
openaire   +1 more source

Fabrication and alignment issues for segmented mirror telescopes

Applied Optics, 2004
There 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, James H, Burge, Rene, Zehnder, Yanqui, Wang   +3 more
openaire   +2 more sources

Segmented Mirrors For Atmospheric Compensation

SPIE Proceedings, 1989
An optical wavefront propagating through the atmosphere will be perturbed by local variations in the refractive index of the atmospheric gases. When accumulated over long optical path distances they will impart a spatial and temporally random distortion to the wavefront.
openaire   +1 more source