Wavefront reconstruction from modulated Pyramid ...
Recommend Documents
Introduction - Pyramid Wavefront Sensor. Pupil fragmentation. Split Approach. Summary. Wavefront reconstruction with pyramid sensors and pupil fragmentation.
Table 2 shows the dependence of reconstruction precision of singe-shear ... Deviation of reconstructed phase from original phase using singe-shear versus.
Dec 20, 2012 - reconstruct the wavefront aberrations from tangential refractive power data measured with dynamic skiascopy. ... An extension of this technology, spatial dynamic .... solution could be found if the curvature function were known.
In optical metrology, long-wave interferometers are also employed for ... record also three-dimensional objects using interference between an object wave and a reference ...... The spatial profile of the laser is set in the fundamental TEM00.
Jan 23, 2006 - A new adaptive optics system for the eye using a pyramid ..... mounted on micrometric linear stages provided the necessary head stability and.
Jul 11, 2018 - A visible pyramid wavefront sensor (PWFS) optimized for sensing at .... The red-light path is the science path that goes to the coronagraph.
Wavefront reconstruction from modulated Pyramid ...
Wavefront reconstruction from modulated Pyramid WFS ... and with Giza Pyramids. Credit: ... Theoretical model based on Fourier optics â complex, non-linear.
Inverse problems in Adaptive Optics (AO)
Forward operator to be inverted
Iterative inversion with CGNE
Numerical examples
Wavefront reconstruction from modulated Pyramid WFS measurements in XAO Iuliia Shatokhina and Ronny Ramlau Industrial Mathematics Institute, JKU, Linz
OCIP2012, Munich
March 12-14, 2012
Inverse problems in Adaptive Optics (AO)
Forward operator to be inverted
Iterative inversion with CGNE
Outline
1
Inverse problems in Adaptive Optics (AO)
2
Forward operator to be inverted
3
Iterative inversion with CGNE
4
Numerical examples
Numerical examples
Inverse problems in Adaptive Optics (AO)
Forward operator to be inverted
Iterative inversion with CGNE
Numerical examples
Project
In 2009 Austria joined the European Southern Observatory (ESO). Austrian in-kind project ”Mathematical algorithms and software for ELT adaptive optics” for ESO, October 2009 - October 2013
The ESO Headquarters in Garching, Munich. Credit: ESO
Inverse problems in Adaptive Optics (AO)
Forward operator to be inverted
Iterative inversion with CGNE
Numerical examples
Our group Austrian Adaptive Optics (AAO) group in Linz, Austria: Industrial Mathematics Institute Johann Radon Institute for Computational and Applied Mathematics (RICAM) Industrial Mathematics Competence Center (IMCC)
ELT - Extremely Large Telescope: year 2020, mirror diameter 40 m. Credit: ESO
Inverse problems in Adaptive Optics (AO)
Forward operator to be inverted
Iterative inversion with CGNE
Numerical examples
ELT
E-ELT and VLT sizes compared with Colosseum
E-ELT on a mountaintop in Chile’s Atacama Desert. The E-ELT will be the largest optical/infrared telescope in the world. Credit: ESO
and with Giza Pyramids. Credit: ESO → There are still goals to be reached :)
Inverse problems in Adaptive Optics (AO)
Forward operator to be inverted
Iterative inversion with CGNE
Numerical examples
Problem
Light is directed to the wavefront sensor (WFS) which produces the measurements s = Qφ. Problem: given the measurements s, reconstruct the unknown distorted wavefront φ. And ... Credit: Wiki
Inverse problems in Adaptive Optics (AO)
Forward operator to be inverted
Iterative inversion with CGNE
General AO scheme
... and in real time apply the corresponding commands to the actuators of the deformable mirror (DM).
Credit: A.Tokovinin Credit: ESO
Numerical examples
Inverse problems in Adaptive Optics (AO)
Forward operator to be inverted
Iterative inversion with CGNE
Numerical examples
AO benefits
Left - a blurred image without AO correction, right - the AO corrections reveal a binary star. Credit: C.Beichman, A.Tanner Images of Uranus without and with AO correction. Credit: WHT The nuclear region of the nearby galaxy NGC 7469, without and with AO. Credit: CFHT
Inverse problems in Adaptive Optics (AO)
Forward operator to be inverted
Iterative inversion with CGNE
Numerical examples
eXtreme Adaptive Optics (XAO)
One of the four subprojects Application - direct imaging of extrasolar planets Extremely difficult because of the overwhelming light from the nearby star (sun) Artist’s impression. Credit: ESO Specifications: Deformable mirror and WFS with 200 × 200 subapertures Pyramid WFS, non-modulated and modulated Frequency of AO loop 3KHz Speed requirement: reconstruction time 0.3ms, to be faster than MVM Quality requirement: Strehl ratio 96% (typical measure in astronomy)
Inverse problems in Adaptive Optics (AO)
Forward operator to be inverted
Iterative inversion with CGNE
Numerical examples
Pyramid WFS
Pyramidal prism in lab. ´ Credit: C. Verinaud.
Measurements: Sx = (I1 + I4 ) − (I2 + I3 ) Sy = (I1 + I2 ) − (I3 + I4 ) ´ Credit: C. Verinaud. Circular modulation path, α — modulation radius. Theoretical model based on Fourier optics — complex, non-linear.
Inverse problems in Adaptive Optics (AO)
Forward operator to be inverted
Iterative inversion with CGNE
Roof WFS
´ Credit: C. Verinaud. Simplifying assumptions: Roof WFS with sinusoidal modulation. Linearized model, valid in the closed AO loop φ
