Results 21 to 30 of about 145,188 (319)

ALFA: First Operational Experience of the MPE/MPIA Laser Guide Star System for Adaptive Optics [PDF]

open access: yes, 1998
The sodium laser guide star adaptive optics system ALFA has been constructed at the Calar Alto 3.5-m telescope. Following the first detection of the laser beacon on the wavefront sensor in 1997 the system is now being optimized for best performance.
Davies, R. I.   +7 more
core   +3 more sources

Adaptive Optics Tip-Tilt Correction Based on Smith Predictor and Filter-Optimized Linear Active Disturbance Rejection Control Method

open access: yesSensors, 2023
A tip-tilt mirror (TTM) control method is designed to enhance the control bandwidth and ensure the rejection performance of the adaptive optics (AO) tip-tilt correction system.
Lingxi Kong   +6 more
doaj   +1 more source

Centroid-Predicted Deep Neural Network in Shack-Hartmann Sensors

open access: yesIEEE Photonics Journal, 2022
The Shack-Hartmann wavefront sensor produces incorrect wavefront measurements when some sub-spots are weak and missing. In this paper, a method is proposed to predict the centroids of these sub-spots for the Shack-Hartmann wavefront sensor based on the ...
Mengmeng Zhao   +6 more
doaj   +1 more source

The Extreme Learning Machine for the Extraction of Mono-Exponential Decay Time

open access: yesIEEE Photonics Journal, 2023
The mono-exponential decay has been used to describe various physical phenomena such as cavity ring-down signal, fluorescence decay, etc. In this paper, a neural network method of extreme learning machine (ELM) is adopted to efficiently extract decay ...
Xing He   +4 more
doaj   +1 more source

Adaptive Optics for Astronomy

open access: yes, 2012
Adaptive Optics is a prime example of how progress in observational astronomy can be driven by technological developments. At many observatories it is now considered to be part of a standard instrumentation suite, enabling ground-based telescopes to ...
Arsenault R   +22 more
core   +1 more source

Real-time turbulence profiling with a pair of laser guide star Shack–Hartmann wavefront sensors for wide-field adaptive optics systems on large to extremely large telescopes [PDF]

open access: yes, 2010
Real-time turbulence profiling is necessary to tune tomographic wavefront reconstruction algorithms for wide-field adaptive optics (AO) systems on large to extremely large telescopes, and to perform a variety of image post-processing tasks involving ...
Ellerbroek, B. L., Gilles, L.
core   +1 more source

Design and Experimental Validation of a Model-Free Controller for Beam Stabilization in Adaptive Optics Systems

open access: yesIEEE Photonics Journal
Stabilization of optical beams has always been a key factor affecting the performance of many optical systems. The Adaptive optics (AO) beam stabilization system requires further development to cope with increasingly complex application scenarios and ...
Sicheng Guo   +6 more
doaj   +1 more source

Adaptive Optics for Extremely Large Telescopes

open access: yes, 2019
Adaptive Optics has become a key technology for the largest ground-based telescopes currently under or close to begin of construction. Adaptive optics is an indispensable component and has basically only one task, that is to operate the telescope at its ...
Hippler, Stefan
core   +1 more source

Optimization of Iterative Control Algorithms for High-Resolution Adaptive Optics Systems

open access: yesIEEE Photonics Journal
As the number of wavefront sensor subapertures and deformable mirror actuators in adaptive optics systems increases, the computational time of the direct gradient wavefront control algorithm is excessively long, which is a major factor affecting the ...
Shenghu Liu   +7 more
doaj   +1 more source

Robust control of a bimorph mirror for adaptive optics system [PDF]

open access: yes, 2008
We apply robust control technics to an adaptive optics system including a dynamic model of the deformable mirror. The dynamic model of the mirror is a modification of the usual plate equation. We propose also a state-space approach to model the turbulent
Arzelier, Denis   +3 more
core   +2 more sources

Home - About - Disclaimer - Privacy