AOF Wave front sensor modules GALACSI and GRAAL by Stefan Ströbele in behalf of the GALACSI and...
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Transcript of AOF Wave front sensor modules GALACSI and GRAAL by Stefan Ströbele in behalf of the GALACSI and...
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