aof wave front sensor modules galacsi and graal by stefan ströbele in behalf of the galacsi and...
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AOF Wave front sensor modules
GALACSI and GRAALby
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 groups20 Years AO@ESO 1
GRAAL- GALACSI Comparison
20 Years AO@ESO 2
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 K-band) x1.7 EE gain x2 EE gain S.R. >5% (10% goal)
@650nmNatural Guide Stars On axis, ~ 8 mag R-mag 14.5 within
6.7’ to 7.7’ radiusR-mag <17.5 within 52” to 105” radius
On Axis, NIR, Jmag 15Low Order sensing
Sky coverage Close to “bright” stars 95% >90% Science target =
TT reference
4LGSF config. NGS only Ø12’ Ø2’ Ø20”
WFS1 NGS L3-CCD(40*40 sub app.)
4 LGS L3-CCD (40*40 sub app.)1 TT L3-CCD
4 LGS L3-CCD(40*40 sub app.)1 TT L3-CCD
4 LGS L3-CCD(40*40 sub app.)1 IR Low Order
Loop frequency HO loop: ≥ 700 Hz HO loop: ≥ 700 HzTT loop: 250Hz
HO loop: 1 kHzTT loop: 200Hz
HO loop: 1 kHzLO loop: 200-500Hz
AO Types• SCAO:
– 1 Natural guide star, 1 WFS– WFS measures Turbulence– correction by the DM
4
• 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
20 Years AO@ESO 5
Altitude [km]
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
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
20 Years AO@ESO 6
• Integration to a existing instrument
Strong constraints to space, weight, access, interfaces
GRAAL big pieces
20 Years AO@ESO 7
Hawk-I shutter
Alu-structur
e
Steel structur
e
bearingTorqu
e drive
Steel flange
LGS trombone
LGS WFS assembly
NGS-TT sensor assembly
MCM assembly
•Bearing (150Nm friction / 80kg)
•Torque drive (500Nm nominal / 70kg)
•Encoder (tape / scanning head)
•Cable-guide system (110 kg)
• Aluminium structure (75 kg)
•Steel structure (50 kg)
Counterweight
GRAAL as seen from (above) the Nasmyth platform
Flange sandwiched between UT-Nasmyth and Hawk-I
Aluminum and steel structure for stiffness and weight constraints
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
Internal co-rotator for pupil derotation, direct drive in torque mode, strip band encoder, control loop using VLT-SW standard library
100 kg counterweight to balance 150 kg of electronics
ICPs for quick-separation
GRAAL arrangement on UT4• 2 E-Cabinet on board
– (WFS camera electronics)
• Uses the HAWK-I cable rotator
• Cabinet on the NP – motion control,
• Cabinet on Azimuth PF– SPARTA RTC– 5*NGC backend
• Cabinet in the computer room– SPARTA cluster
20 Years AO@ESO 9
WFS Cabinet 4
HAWK-I
Motion Control Cabinet
SC
P
GRAAL
SC
P
Cable rotatorHawk-I
Na
sm
yth
P
latf
orm
WFS Cabinet 3
RT
C
Azi
mu
th
Pla
tfo
rm
GRAAL Performance
• Image improvement x~2 (EE in 0.1” pixel),Image improvement x~2 (EE in 0.1” pixel),seeing reducer: x0.8 (in Ks)seeing reducer: x0.8 (in Ks)
• Improvement for all seeing conditionsImprovement for all seeing conditions
J. Paufique GRAAL FDR, 10/03/2009
0
10
20
30
40
50
60
70
80
90
100
0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
rela
tiv
e f
req
ue
nc
y (
arb
itra
ry u
nit
s)
theta50 in K-band (")
compared seeing with/without GRAAL
without
with GRAAL
statistics 1999-2004L0 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)
0.4 0.7 1.1 1.6 (open loop seeing at 0.5µm)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40
K-band image quality
cum
ula
tive
fre
qu
ency
without
with GRAAL
MUSE-GALACSIMUSE:
– 3d Spectrograph with 300 by 300 spatial resolution elements
– Spectrometer resolution 1500-3000
– 24 spectrographs with 1CCD 4096 by 4096 pixels each
– Wavelength range: 465-930nm – Developed by consortium lead by
CRA-Lyon, PI: R.Bacon
• Nasmyth platform “over” filled (Volume, Weight)
extension for cabinets and access
20 Years AO@ESO 11
GALACSI –FDR 16th June 2009 12
WFM
1’ MUSE FOV
1 faint NGS within 3.4’
FOV
4 Sodium LGSs
Rayleigh cone
NFM
NGS-LGS Configurations
20 Years AO@ESO 13
LGS WFS path
14
14:41:12
New lens from CVMACRO:cvnewlens.seq 10-Apr-08
120.00 MM
Annular Mirror, ( no obstruction for MUSE WFM)LGS dichroic inserted for NFM
WFS, LA
LGS
dic
hroi
c,
Ref
lect
s 58
9nm
tran
smits
th
e re
st t
o T
TS
Pupil relay
Tel
ecen
tric
ity le
ns
Foc
us c
ompe
nsat
orPyramid:•LGS separation near LGS focus•On linear stage to switch between modes
Jitter actuator
2nd Pupil relay
from
VLT
AIT
pup
il
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 15
IRLOS
AO Facility Review, 24.04.08 16
• 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
GALACSI Performance
20 Years AO@ESO 17
specification
WFM performance
NFM performance
Outlook to GRAAL
Commissioning
20 Years AO@ESO 18
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