Transcript AOF Wave front sensor modules GALACSI and GRAAL by Stefan Ströbele in behalf of the GALACSI and GRAAL Team members: R.Arsenault, R.Conzelmann, B.Delabre, R.

AOF
Wave front sensor modules
GALACSI and GRAAL
by
Stefan Ströbele
in behalf of the GALACSI and GRAAL Team members:
R.Arsenault, R.Conzelmann, B.Delabre, R. Donaldson, M.Duchateau,
G.Hess, P.Jolley, A. Jost, M.Kiekebusch, M.Lelouarn, P.Y.Madec,
A.Manescau, J.Pirard, J.Quentin, R.Siebenmorgen, C.Soenke, S.Tordo,
J.Vernet,
SPARTA, DSM, 4LGS, ASSIST, Teams,
Integration and IR and CCD detector groups
20 Years AO@ESO
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GRAAL- GALACSI Comparison
parameter
GRAAL
GALACSI
Instrument
Hawk-I (IR imager) ESO
Muse (VIS 3D-spectrograph) Lyon
Mode
Maintenance mode
GLAO
Wide Field Mode
Narrow Field Mode
Field of view
10”
7.5’
1’
7.5”
AO mode
SCAO
GLAO
GLAO
LTAO
Performance
(S.R. ~ 80% in Kband)
x1.7 EE gain
x2 EE gain
Natural Guide
Stars
On axis, ~ 8 mag
R-mag 14.5 within
6.7’ to 7.7’ radius
R-mag <17.5 within
52” to 105” radius
Sky coverage
Close to “bright”
stars
95%
>90%
4LGSF config.
NGS only
Ø12’
Ø2’
Ø20”
WFS
1 NGS L3-CCD
(40*40 sub app.)
Loop frequency
HO loop: ≥ 700 Hz
4 LGS L3-CCD
(40*40 sub app.)
1 TT L3-CCD
HO loop: ≥ 700 Hz
TT loop: 250Hz
4 LGS L3-CCD
(40*40 sub app.)
1 TT L3-CCD
HO loop: 1 kHz
TT loop: 200Hz
4 LGS L3-CCD
(40*40 sub app.)
1 IR Low Order
HO loop: 1 kHz
LO loop: 200-500Hz
20 Years AO@ESO
S.R. >5% (10% goal)
@650nm
On Axis, NIR, Jmag 15
Low Order sensing
Science target =
TT reference
2
AO Types
• SCAO:
– 1 Natural guide star, 1 WFS
– WFS measures Turbulence
– correction by the DM
• GLAO:
– 4 Laser guide stars, 4 WFSs
– 1 Natural guide star, 1 TT Sens.
– Average WFS signal High order
DM command + tip tilt meas.
• LTAO:
– 4 Laser guide stars, 4 WFSs
(closer together)
– 1 Natural guide star, 1 low order
sensor
– WFS signal + Tomography
Algorithm  high order DM
command + tip tilt +focus meas.
– correction by the DM
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Altitude
[km]
20 Years AO@ESO
LGS
beam Ø
[m]
Beam offset [m]
GRAAL
GALACSI
WFM
GALACSI
NFM
LGS at 6’
LGS at 64”
LGS at 10”
0
8
0
0
0
1.4
7.86
2.6
0.5
0.07
2.2
7.8
3.9
0.7
0.1
11.2
6.9
-
3.5
0.5
16
6.6
-
-
0.8
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GRAAL
• LGS and NGS pickup
outside the science field
• HAWK-I co-rotates to the
sky
• Matching of the WFS –
DSM geometries
counter rotation of the LGS
WFSs
• Integration to a existing
instrument
 Strong constraints to
space, weight, access,
20 Years AO@ESO
interfaces
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GRAAL big pieces
Alustructure
NGS-TT sensor
assembly
LGS trombone
LGS WFS assembly
bearing
Hawk-I
shutter
Torque
drive
Steel
structure
Counterweight
Steel
flange
MCM
assembly
•Bearing (150Nm friction / 80kg)
•Torque drive (500Nm nominal / 70kg)
•Encoder (tape / scanning head)
•Cable-guide system (110 kg)
• Aluminium structure (75 kg)
20 Years AO@ESO
•Steel structure (50 kg)
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GRAAL as seen from (above) the Nasmyth platform
Flange sandwiched between UTNasmyth and Hawk-I
Aluminum and steel structure for
stiffness and weight constraints
ICPs for quick-separation
Internal co-rotator for pupil
derotation, direct drive in torque
mode, strip band encoder, control
loop using VLT-SW standard library
1kHz, 0-noise LGS WFS, optics
and trombone focusing on a Ø500
mm (x4)
Retractable focal enlarger x6
(maintenance and commissioning),
with WFS pick-up
100 kg counterweight to balance
150 kg of electronics
GRAAL arrangement on UT4
• 2 E-Cabinet on board
– SPARTA RTC
– 5*NGC backend
• Cabinet in the computer
room
– SPARTA cluster
20 Years AO@ESO
Azimuth
Platform
• Cabinet on Azimuth PF
HAWK-I
RTC
– motion control,
GRAAL
SCP
• Uses the HAWK-I cable
rotator
• Cabinet on the NP
WFS
Cabinet 4
SCP
WFS
Cabinet 3
(WFS camera electronics)
Motion
Control
Cabinet
Nasmyth
Platform
–
Cable rotator
Hawk-I
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GRAAL Performance
• Image improvement x~2 (EE in 0.1” pixel),
seeing reducer: x0.8 (in Ks)
• Improvement for all seeing conditions
0.4
0.7
1.1
1.6
cumulative frequency
compared seeing with/without GRAAL
(open loop seeing at 0.5µm)
relative frequency (arbitrary units)
100
90
without
80
with GRAAL
70
statistics 1999-2004
L0 assumed of 25 m, pointing at zenith
<= 0.2": results are not representative of the
image quality (dif f raction, vibrations, telescope and
residual errors become dominant)
60
50
40
30
90%
80%
70%
60%
without
50%
with GRAAL
40%
30%
20%
20
10%
10
0
0.00
100%
0%
0.00
0.20
J. Paufique
0.40
0.60
0.80
1.00
theta50 in K-band (")
1.20
1.40
1.60
0.20
0.40
0.60
0.80
1.00
1.20
K-band image quality
GRAAL FDR, 10/03/2009
1.40
MUSE-GALACSI
MUSE:
– 3d Spectrograph with
300 by 300 spatial
resolution elements
– Spectrometer resolution
1500-3000
– 24 spectrographs with
1CCD 4096 by 4096
pixels each
– Wavelength range: 465930nm
– Developed by
consortium lead by CRALyon, PI: R.Bacon
20 Years AO@ESO
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NGS-LGS Configurations
WFM
1’ MUSE FOV
1 faint NGS
within 3.4’
FOV
GALACSI –FDR 16th June 2009
NFM
4 Sodium
LGSs
Rayleigh
cone
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20 Years AO@ESO
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AIT pupil
Focus compensator
from VLT
Reflects 589nm
transmits the rest to TTS
LGS dichroic,
Telecentricity lens
LGS WFS path
14:41:12
Pyramid:
•LGS separation near LGS
focus
•On linear stage to switch
between modes
2nd Pupil relay
Annular Mirror,
( no obstruction for MUSE WFM)
LGS dichroic inserted for NFM
New lens from CVMACRO:cvnewlens.seq
Pupil relay
WFS, LA
120.00
MM
Jitter
actuator
10-Apr-08
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GALACSI Main assembly
• GALACSI at
Nasmyth B UT4
• 5 E-Boxes on
board
• 1 Cabinet on NP
• 1 Cabinet on AZ P
• 2 cable chains
AO Facility Review, 24.04.08
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IRLOS
• HAWAI –I 1024 x 1024 pixels, 4 quadrant
geometry  4 sub aperture lenslet array
• Frame rate 200/500 Hz for 20by20/8by8 pix
RON <15 e-rms
AO Facility Review, 24.04.08
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GALACSI Performance
specification
NFM performance
WFM performance
20 Years AO@ESO
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Outlook to
GRAAL
Commissioning
20 Years AO@ESO
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