Results 21 to 30 of about 345,237 (255)
Spatial Spectrum Analysis of Wave-Front Correction with a Segmented Mirror [PDF]
, 2003 An expression is derived for the spatial power spectrum of wave-front errors after correction with a segmented mirror. This includes estimates of the spectral contributions of segment piston and tilt corrections and spatial aliasing by a regular array of
Padin, Stephen
core +1 more source
Confusion in differential piston measurement with the pyramid wavefront sensor
Astronomy & Astrophysics, 2021 Context. The pyramid was proven to be a highly sensitive and versatile wave-front sensor (WFS) and has been selected to be installed on the single conjugate adaptive optics (AO) systems of the extremely large telescope (ELT).
A. Bertrou-Cantou +6 more
semanticscholar +1 more source
Optical-approximation analysis of sidewall-spacing effects on the force between two squares with parallel sidewalls [PDF]
, 2007 Using the ray-optics approximation, we analyze the Casimir force in a two dimensional domain formed by two metallic blocks adjacent to parallel metallic sidewalls, which are separated from the blocks by a finite distance h.
Jaffe, Robert L. +3 more
core +1 more source
Optics Express, 2021 To realize the large-scale and high-precision co-phasing adjustment of synthetic-aperture telescopes, we propose a multichannel left-subtract-right feature vector piston error detection method based on a convolutional neural network, which inherits the ...
Pengfei Wang +5 more
semanticscholar +1 more source
Tests with a Carlina-type diluted telescope; Primary coherencing [PDF]
, 2012 Studies are under way to propose a new generation of post-VLTI interferometers. The Carlina concept studied at the Haute- Provence Observatory is one of the proposed solutions. It consists in an optical interferometer configured like a diluted version of
A. Le Vansuu +37 more
core +3 more sources
Atmospheric coherence times in interferometry: definition and measurement [PDF]
, 2006 Current and future ground-based interferometers require knowledge of the atmospheric time constant t_0, but this parameter has diverse definitions. Moreover, adequate techniques for monitoring t_0 still have to be implemented.
A. Kellerer +18 more
core +2 more sources
IEEE Photonics Journal, 2017 A novel approach of tip/tilt control through optimizing laser beam coupling efficiencies from space to polarization-maintaining-fibers with stochastic parallel gradient descent (SPGD) algorithm for coherent beam combining (CBC) applications is ...
Feng Li +5 more
doaj +1 more source
Shack-Hartmann wavefront sensing with elongated sodium laser beacons: centroiding versus matched filtering [PDF]
, 2006 We describe modeling and simulation results for the Thirty Meter Telescope on the degradation of sodium laser guide star Shack-Hartmann wavefront sensor measurement accuracy that will occur due to the spatial structure and temporal variations of the ...
Ellerbroek, Brent, Gilles, Luc
core +1 more source
Operation of a MOEMS Deformable Mirror in Cryo: Challenges and Results
Micromachines, 2017 Micro-opto-electro-mechanical systems (MOEMS) Deformable Mirrors (DM) are key components for next generation optical instruments implementing innovative adaptive optics systems, both in existing telescopes and in the future ELTs.
Frederic Zamkotsian +5 more
doaj +1 more source
Scientific Reports, 2017 In this paper, we experimentally validate a tiled-aperture conformal projection system with the largest array filling factor and element beam truncation factor to the best of our knowledge. The conformal projection system, which is made up of a hexagonal
Dong Zhi +7 more
doaj +1 more source