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Fast E2E simulation tools and calibration strategies for EAGLE-MOAO on the E-ELT. Manal Chebbo, Alastair Basden , Richard Myers, Nazim Bharmal , Tim Morris, Thierry Fusco, Jean-Francois Sauvage. - PowerPoint PPT Presentation
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Manal Chebbo AO4ELT3 30 May 2013 1
Manal Chebbo, Alastair Basden, Richard Myers, Nazim Bharmal, Tim Morris, Thierry Fusco, Jean-Francois Sauvage
Fast E2E simulation tools and calibration strategies for EAGLE-MOAO on the E-ELT
Manal Chebbo AO4ELT3 30 May 2013 2
DASP VS E2E-SDurham Ao Simulation Platform VS E2E- Sparse (LAM / ONERA)
Conventional MVM dense Sparse methods utilized.
Atmosphere to Slopes slow but accurate model.
Typically needs to run for several hours to simulate 10 – 100 s of operational time, but with high fidelity…
Sparse methods only.
Atmosphere to Slopes fast but approximated model.
Speed comparable to analytical codes, but capabilities of E2E codes, for ex: Optical tolerance studies…
Basden et al 2007Chebbo et al 2011
AO4ELT2
Manal Chebbo AO4ELT3 30 May 2013
Synopsis
3
1. Sparse E2E Simulator2. DASP Simulator3. Conclusion and Perspective
Manal Chebbo AO4ELT3 30 May 2013
Synopsis
4
1. Sparse E2E Simulator
2.DASP Sim
ulator
3. Conclusion and Perspective
Manal Chebbo AO4ELT3 30 May 2013 5
Sparse E2E Simulator
AO in blocks
Configuration system
Turbulent generator
WFS model
Tomographic reconstructor
DM model
Manal Chebbo AO4ELT3 30 May 2013 6
Sparse E2E Simulator Description of the different modules
Configuration System
Manal Chebbo AO4ELT3 30 May 2013 7
Sparse E2E Simulator Description of the different modules
Turbulence generator
Generate layers in the form of pixilated phase screen
Simulation and computation of white noise FT Inverse FT → real part d/r0
Wind speed, direction for the considered layer
Manal Chebbo AO4ELT3 30 May 2013 8
Sparse E2E Simulator Description of the different modules
Wave Front Sensor Sparse-Model
➜ Realistic sparse Geometry Model of Shack- Hartman WFS
Illuminated and partly illuminated subapertures are managed
400 subapertures / 308 are fully or partly illuminated in the pupil
• RCO/RCO_d FORMAT : (Representation Complete and Ordered)
Ds = {rco} Ds.r = 2* Ns2
Ds.c = N2
Ds.n = 4* nb_pix* Ns2
Ds.ix = ptr_new([0,make_array(D.r, /long)]) Ds.jx = ptr_new(lonarr(D.n + bandwidth)) Ds.xn = ptr_new(make_array(D.n+ bandwidth, /float))
Manal Chebbo AO4ELT3 30 May 2013 9
Sparse E2E Simulator Description of the different modules
Sparse Wave Front Reconstruction
Sparse noise covariance matrix Cn
Noise are not correlated noise is uniform →
Turbulence covariance matrix
Manal Chebbo AO4ELT3 30 May 2013 10
Sparse E2E Simulator Description of the different modules
Deformable Mirror sparse-Model
➜ DM with sparse influence functions
Ifs profile ~ double Gaussian IF = 0 beyond Nacinf
Fs → RCO → [ N2 , Nact-valid]
64*64 actuators , Nacinf= 4 Nacinf= 6
30% of mechanical coupling for minimizing the fitting error.
Manal Chebbo AO4ELT3 30 May 2013 11
Sparse E2E Simulator Challenges of AO with Tomography
Tip, Tilt and Defocus Indetermination
➜ Goal: Generate realistic WFS measurement’s with filtered out TTF
We modify the slopes to remove any tip tilt or defocus
S
TTF
Manal Chebbo AO4ELT3 30 May 2013 12
Sparse E2E Simulator Challenges of AO with Tomography
Tip, Tilt and Defocus Indetermination
We search the transformation matrix M to an orthogonal space which exludes TTF
2 methods present : ? Setting mean slopes to zero.
? M contain all the modes generated by the AO system.
Manal Chebbo AO4ELT3 30 May 2013 13
Sparse E2E Simulator Challenges of AO with Tomography
Tip, Tilt and Defocus IndeterminationM
ethod-1
TT is reduced to 7% Defocus is not filtered
Subtraction of average slopes
Manal Chebbo AO4ELT3 30 May 2013 14
Challenges of AO with Tomography Tip, Tilt and Defocus Indetermination
M contains the WFS answer to all the modes generated by the system
Method - 2
Karhunen–Loève
TTF are filtered out
Manal Chebbo AO4ELT3 30 May 2013
Synopsis
15
2. DASP Simulator
3.Conclusion and Perspective
1.Sparse E2E Sim
ulator
Manal Chebbo AO4ELT3 30 May 2013 16
DASP VS E2E-S
Conventional MVM denseSparse methods utilized.
Atmosphere to Slopes slow but accurate model.
No, Simple only TT
Sparse methods only.
Atmosphere to Slopes fast but approximated model
TTF filtered out.
Basden et al 2007 Chebbo et al 2011 AO4ELT2
Manal Chebbo AO4ELT3 30 May 2013 17
DASP
● Durham AO Simulation Platform● Python and C● MPI, shared memory, and multi-threaded● Suitable for ELT-scale problems● Cross checked with other codes: Octopus (42
m), YAO (4.2 m), Fourier (ONERA) (42 m)...
Manal Chebbo AO4ELT3 30 May 2013 18
DASP EAGLE E2E DASP-simulations
Simulation Parameter:
42 m, central obscuration = 6 m
R0 = 13.5 cm @ 500 nm.
L0= 30 m
SH With 84*84
LGS closed loop GLAO with M4 and the same with open loop correction on the MOAO DM
40 s of telescope time (10000 iterations)
No NGS , 6 LGS in a regular hexagon
Manal Chebbo AO4ELT3 30 May 2013 19
DASP EAGLE E2E DASP-simulations
H-band Ensquared energy in 75mas over the field of view. 6 LGS at 7.3arcmin diameter 6 LGS, 7.3 arcminute diameter
Strehl Map
Manal Chebbo AO4ELT3 30 May 2013 20
Actuators required
● By making use of global M4 GLAO correction
– Can reduce requirements for MOAO DMs
– MOAO can be relaxed somewhat without dramatically affecting AO performance.
● To ones that can be bought today!
DASP EAGLE E2E DASP-simulations
Manal Chebbo AO4ELT3 30 May 2013
● Steep fall with rotation● 0.2 degrees
● ~1/8th subap at edges
21
Alignment tolerance
● Lateral misalignment reduces performance– Up to 1/8th of a sub-aperture has small
effect
DASP EAGLE E2E DASP-simulations
Rotational tolerance
Manal Chebbo AO4ELT3 30 May 2013 22
Conclusion:
Current Project is to produce a new validated rapid E2E simulation which combines the speed advantages of analytic codes with the ease performing engineering tolerance analysis, for example: Rotational and misalignment
Future Work:
Cross check the codes New user interface for E2E-S code Aim to produce a new form of systems engineering for ELT scale AO problems.
Manal Chebbo AO4ELT3 30 May 2013 2323
Thank You
Manal Chebbo AO4ELT3 30 May 2013 24
Comparison with other codes