CHARA Collaboration Year-Seven Science Review
Telescope Alignment and Wavefront SensingLaszlo Sturmann
Atlanta 2011
CHARA Collaboration Year-Seven Science Review
• 2001-2010 Wavefront is computed from its Laplacian (Roddier)
• 2010 Wavefront is computed from its gradient (Shack-Hartmann Sensor)
Wavefront Evaluation at CHARA
ef
FrontSurfer
not for alignment
better for alignment
CHARA Collaboration Year-Seven Science Review
Optical Setup
25 mm eyepiece
reticle
LED
projector
beam splitterfocal plane
green filter
40 mm collimator
WFS
OKO Standard Config. #1
Hexagonal array
127 lenses,0.3 mm pitch
F=18 mm.
CCD
FrontSurfer
Wavefront expanded into Zernike polynomials
CHARA Collaboration Year-Seven Science Review
Eye Video camera
collimator
eyepiece
reticle
projector
TAS interface
pupil 3.9 mm
CHARA Collaboration Year-Seven Science Review
9/13/2010
PINHOLE SOURCE, TAS OBJECTIVE
31
11
8
1
7
2
28
11
10
9
8
7
6
5
Z
Z
Z
Z
Z
Z
Z
PINHOLE SOURCE, TAS COMPLETE
50x452ms EXPOSURE OF VEGA
nm
nm
152VP
17RMS
95.0Strehl
ZERNIKES [nm]
nm
nm
196VP
22RMS
92.0Strehl
6
18
24
22
25
27
15
11
10
9
8
7
6
5
Z
Z
Z
Z
Z
Z
Z
TAS
nm
nm
237VP
27RMS
89.0Strehl
41
22
25
31
25
36
7
11
10
9
8
7
6
5
Z
Z
Z
Z
Z
Z
Z
contours in nm
E1 9/28/2010
90
66
0
5
114
141
58
11
10
9
8
7
6
5
Z
Z
Z
Z
Z
Z
Z
nm
nm
558VP
78RMS
35.0Strehl
1000 x 10ms exposures of Vega
1600 nm 2200 nm540 nm
WAVEFRONT MAP
89.0Strehl 94.0Strehl
ZERNIKES [nm]
contours in nm
CALIBRATION px
m907.9
m922.9
CHARA Collaboration Year-Seven Science Review
E2 9/17/2010
nm
nm
606VP
95RMS
14.0Strehl
1000 x 10ms exposures of Vega
1600 nm 2200 nm540 nm
WAVEFRONT MAP
82.0Strehl 90.0Strehl
ZERNIKES [nm]
149
166
158
53
154
41
55
11
10
9
8
7
6
5
Z
Z
Z
Z
Z
Z
Z
contours in nm
S1 9/23/2010
147
40
14
27
307
226
568
11
10
9
8
7
6
5
Z
Z
Z
Z
Z
Z
Z
nm
nm
1211VP
231RMS
02.0Strehl
1000 x 10ms exposures of Vega
1600 nm 2200 nm540 nm
WAVEFRONT MAP
26.0Strehl 52.0Strehl
ZERNIKES [nm]
contours in nm
contours in nm
CHARA Collaboration Year-Seven Science Review
re-center star by tilting
the telescope
WFS :
comaZZ2
8
2
7
115 ,..., ZZ
tilt M2N
astZZ2
6
2
5
Y
tilt M1N re-center star by tilting
M2
focus
center star in WFSTWEAKING ALGORITHM
BASED ON SIMULATIONS
Y
CHARA Collaboration Year-Seven Science Review
A
B
C
M2
DIAL INDICATOR
ACTUATOR
ORTHOGONAL AZ-EL ADJUSTMENT AT M2 BUT NOT AT M1
EL
AZ
SOFTWARE
CHARA Collaboration Year-Seven Science Review
AST COMA TREFOIL
Z4
Z5
Z6
Z7
Z8
Z9
Z10
Z11
min1
5Z
6Z
7Z
8Z
9Z
10Z
B
A
PUPIL ROTATES WITH TIME
CHARA Collaboration Year-Seven Science Review
02-03-2011 02-12-2011 W1
P-V=1340 nm
RMS=270 nm
P-V=318 nm
RMS=50 nm
1 arcsec1 arcsec
540 nm 540 nm
ASYMMETRIC PUPIL
02/03/11
[nm]
02/12/11
[nm]
540 27
570 145
-175 -41
196 -40
5Z
6Z
7Z
8Z
CHARA Collaboration Year-Seven Science Review
M3
W1 2/12/11
Nikon D80 20s
CHARA Collaboration Year-Seven Science Review
MONTE CARLO SIMULATION
M1 TILT M2 TILT INCIDENT BEAM
1 2
2
x
y
x y
z
)0,,( 11 vu
),,0( 222 wvu
11
2
2
SOLUTION 1 SOLUTION 2
x
z
y
TWO SOLUTIONS AT A GIVEN
M1,M2 LATERAL
DISPLACEMENT
1
CHARA Collaboration Year-Seven Science Review
WFS
FUTURE PLANS:
WHAT IS THIS?
FOCUS INACCESSIBLE
TESTING M1 IN SITU
CHARA Collaboration Year-Seven Science Review
CCD CAMERA
FINDING THE VERTEX OF M1
M1 is F/2.5
VERY SENSITIVE TO MISALIGNMENT
COMA
CHARA Collaboration Year-Seven Science Review
SIMULATED PRIME FOCUS IMAGES
OFF-AXIS ON-AXIS
CHARA Collaboration Year-Seven Science Review
COMA FREE TILTING OF M2
SPHERICAL BEARING
AT THE FOCAL POINT
M2ACTUATORS
CHARA Collaboration Year-Seven Science Review
ODDS & ENDS
• COUDE-BOX COVER
O u t[1 1 2 ]=
15604 15606 15608 15610 15612 1561410
5
0
5
10
15
20
25
JD 2440000.5
E1
OUTSIDE
Temperature C°
• HUMIDITY-TEMPERATURE
SENSORS IN THE DOMES
6h