Results 31 to 40 of about 39,077 (276)

Shape correction of thin mirrors in a reconfigurable modular space telescope [PDF]

, 2010
In order to facilitate the construction of future large space telescopes, the development of low cost, low mass mirrors is necessary. However, such mirrors suffer from a lack of structural stability, stiffness, and shape accuracy.
Breckinridge, James, Patterson, Keith, Pellegrino, Sergio   +2 more
core   +1 more source

A Demonstration of Wavefront Sensing and Mirror Phasing from the Image Domain [PDF]

, 2014
In astronomy and microscopy, distortions in the wavefront affect the dynamic range of a high contrast imaging system. These aberrations are either imposed by a turbulent medium such as the atmosphere, by static or thermal aberrations in the optical path,
Cheetham, Anthony, Cvetojevic, Nick, Martinache, Frantz, Norris, Barnaby, Pope, Benjamin, Tuthill, Peter   +5 more
core   +2 more sources

Design and Research of Large-Scale Curvature Adjustment Optical Mirror

Photonics
This study introduces an optimization design method for large-scale curvature-adjustable optical mirrors, innovatively integrating parametric modeling with the optimized layout of actuators, targeting the achievement of extensive curvature adjustability ...
Kailun Zhao, Liuxing Song, Dewei Sun, Qiaolin Huang, Rongguang Guo, Guoliang Tian, Jinping He   +6 more
doaj   +1 more source

Fizeau interferometric cophasing of segmented mirrors

Optics Express, 2012
Segmented mirror telescope designs address issues of mechanical rigidity, but introduce the problem of aligning, or cophasing, the separate segments to conform to the optimum mirror shape. While several solutions have been widely adopted, a few difficulties persist - the introduction of non-common path errors and an artificial division of the problem ...
Anthony C, Cheetham, Peter G, Tuthill, Anand, Sivaramakrishnan, James P, Lloyd   +3 more
openaire   +2 more sources

Analytical expressions for optimum alignment modes of highly segmented mirrors

, 2004
The major sources causing deterioration of optical quality in extremely large optical telescopes are misadjustments of the mirrors, deformations of monolithic mirrors, and misalignments of segments in segmented mirrors. For active optics corrections, all
Cantrill CD, L. Noethe, Troy M
core   +1 more source

Exploiting Traffic Balancing and Multicast Efficiency in Distributed Video-on-Demand Architectures [PDF]

, 2003
Distributed Video-on-Demand (DVoD) systems are proposed as a solution to the limited streaming capacity and null scalability of centralized systems. In a previous work, we proposed a fully distributed large-scale VoD architecture, called Double P-Tree,
Cores Prado, Fernando, Hernandez, Porfidio, Luque, Emilio, Qazzaz, Bahjat, Ripoll, A., Suppi, Remo, Yang, Xiaoyuan   +6 more
core   +1 more source

Principles and Applications of Interferometry in Highly Segmented Mirrors Co-Phasing

Photonics
With advances in scientific foundations and engineering practice, segmented mirrors—a key architecture for realizing extremely large apertures and high-resolution imaging—have become foundational across space astronomy, ground-based telescopes, and ...
Shijun Song, Xinyue Liu, Tao Chen, Changhua Liu, Qichang An   +4 more
doaj   +1 more source

ADAPTIVE OPTICS WITH SEGMENTED MIRROR OR DEFORMABLE MIRROR

Le Journal de Physique Colloques, 1980
Two kinds of adaptive optics (COAT) are presented : one with segmented mirrors (COAT = 19) with 19 mirrors and actuators and the other with a continuously deformable mirror and 7 actuators. Each mirror of COAT 19 is moved by a piezoelectric actuator performing correction and modulation (dithering in the 12-24 kHz band).
Gaffard, J., Davila, C., de Miscault, J., Roger, G.   +3 more
openaire   +2 more sources

Large Range of a High-Precision, Independent, Sub-Mirror Three-Dimensional Co-Phase Error Sensing and Correction Method via a Mask and Population Algorithm

Sensors
The emergence of segmented mirrors is expected to solve the design, processing, manufacturing, testing, and launching of space telescopes of large apertures.
Dequan Li, Dong Wang, Jingquan Li
doaj   +1 more source

Reshaping Field of View and Resolution with Segmented Reflectors: Bridging the Gap between Rotating and Solid-State LiDARs

Sensors, 2020
This paper describes the first simulations and experimental results of a novel segmented Light Detection And Ranging (LiDAR) reflector. Large portions of the rotating LiDAR data are typically discarded due to occlusion or a misplaced field of view (FOV).
Atle Aalerud, Joacim Dybedal, Dipendra Subedi   +2 more
doaj   +1 more source