PILOT:
Pathfinder for an International Large OpticalTelescope
-performance specifications
JACARA Science Meeting
PILOT
Friday March 26
Anglo Australian Observatory
Jon Lawrence
The data
• Turbulence:
– SODAR (winter 2003/4)– MASS (winter 2004)– DIMM (summer 2003/04)
• Sky temperature and opacity
– SUMMIT (winter 2003/4)– MIR FTI (summer 2003/4)
• Met data
– COBBER (winter 2003/4)– ICECAM (summer 2003/4)– AWS (winter 2004)– met balloons (summer 2000-04)
• Turbulence:
– SODAR (winter 2000/1)– DIMM (winter 2000/01)– microthermals (winter 1996)
• Sky temperature and opacity
– SUMMIT (winter 2003/4)– MIR FTI (summer 2002/3)– MISM (winter 1998)– NISM (winter 2000)
• Met data
– AWS– met balloons
DOME C South Pole
Seeing Data Dome C - 2002/3
DIMM summer 2002: median seeing 1.2 arcsec (Aristidi et al, 2003)
SODAR summer/ winter 2003:median seeing ~0.08 arcsec (33 % floor 0.05)
Seeing Data Dome C - 2003/4
DIMM summer 2003/4:
• data not yet reduced
• median seeing < 1.1 arcsec (~0.4-0.7 arcsec)
• isoplanatic angle ~ 10 arcsec
10 100 1000 100001E-20
1E-19
1E-18
1E-17
1E-16
1E-15
1E-14
1E-13
CN2
(m-2/3
)
Height above ground level (m)
CN2 profile Dome C Bad
r0 = 0.05 m (1.8 arcsec seeing)
r0 = 0.2 m (0.5 arcsec seeing)
iso = 9.5 arcsec fG = 30 Hz
iso = 13.5 arcsec fG = 7 Hz
10 100 1000 100001E-20
1E-19
1E-18
1E-17
1E-16
1E-15
1E-14
1E-13
CN2
(m-2/3
)
Height above ground level (m)
CN2 profile Dome C Good
r0 = 0.05 m (1.8 arcsec seeing)
r0 = 0.7 m (0.15 arcsec seeing)
r0 = 0.2 m (0.5 arcsec seeing)
iso = 9.5 arcsec fG = 30 Hz
iso = 30 arcsec fG = 2Hz
iso = 13.5 arcsec fG = 7 Hz
10 100 1000 100001E-20
1E-19
1E-18
1E-17
1E-16
1E-15
1E-14
1E-13
CN2
(m-2/3
)
Height above ground level (m)
CN2 profile Mauna Kea
iso = 2 arcsec fG = 50 Hz
r0 = 0.20 m (0.50 arcsec seeing)
iso = 9.5 arcsec fG = 30 Hz
r0 = 0.05 m (1.8 arcsec seeing)
iso = 30 arcsec fG = 2Hz
r0 = 0.7 m (0.15 arcsec seeing)
iso = 13.5 arcsec fG = 7 Hz
r0 = 0.2 m (0.50 arcsec seeing)
Atmospheric parameters
seeing (arcsec) isoplanatic angle Greenwood (arcsec) Frequency (Hz)
Mauna Kea 0.50 2-3 50
Dome C 0.15 - 0.50 10-30 2-10
10 100 1000 100001E-20
1E-19
1E-18
1E-17
1E-16
1E-15
1E-14
1E-13
CN2
(m-2/3
)
Height above ground level (m)
10 100 1000 100000
5
10
15
20
25
30
35
40
Wind speed (m.s
-1
)
Height above ground level (m)
Atmospheric parameters
seeing (arcsec) isoplanatic angle Greenwood (arcsec) Frequency (Hz)
Mauna Kea 0.50 2-3 50
Dome C 0.15 - 0.50 10-30 2-10
10 100 1000 100001E-20
1E-19
1E-18
1E-17
1E-16
1E-15
1E-14
1E-13
CN2
(m-2/3
)
Height above ground level (m)
10 100 1000 100000
5
10
15
20
25
30
35
40
Wind speed (m.s
-1
)
Height above ground level (m)
??
Adaptive Optics
wavefront sensor
wavefront analysis
wavefront control
centroid sensordichroicbeam splitters
to tip-tilt secondary
image camera
telescope optics
guide starobject
tip-tilt control
deformable mirror
PILOT AO systems
• Tip-tilt
– tip-tilt mirror + quad sensor
• Low Order AO
– ds=0.3 (30-50 actuators)
• High Order AO
– ds=0.08 (500-1000 actuators)
PILOT AO system performance
• Low Greenwood frequency:– lower feedback loop frequency– higher integration time– fainter stars
lower SNR/bandwidth errors• Large isoplanatic angle
– larger fields– brighter stars
low anisoplanatic error• Better seeing (lower r0)
– less actuators
lower fitting error
Strehl ratio - V band
6 8 10 12 14 16 180.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Strehl Ratio
Guide star magnitude
On-axis low order
DCG
DCBMK
2 4 6 8 10 120.5
0.6
0.7
0.8
0.9
1.0
Strehl Ratio
Star magnitude
Strehl Ratio
Strehl ratio - K band (tip-tilt correction)
6 8 10 12 14 16 18
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Strehl
Magnitude
0 1000.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Strehl
Guide star separation
DCB DCB
DCGDCG
On-axis Off-axis
0.4 1 10
0.1
1
Strehl Width (arcsec)
Wavelength (μ )m
Diff lim 2m
Uncomp DCB
Uncomp DCG
0.4 1 10
0.1
1
Strehl Width (arcsec)
Wavelength (μ )m
Diff lim 2m
DCB off-axis
DCG off-axis
on-axis
Uncomp DCB
Uncomp DCG
0.4 1 10
0.1
1
Strehl Width (arcsec)
Wavelength (μ )m
Diff lim 2m
DCB off-axis
DCG off-axis
on-axis
Uncomp MK
Uncomp DCG
Uncomp DCB
Gemini altair
Diff lim 8 m
0.4 1 10
0.1
1
diffraction limit 2m
Strehl Width (arcsec)
Wavelength (μ )m
8diffraction limit m- on axis AO
- tip tilt correction
Altair on Gemini
Sky emission
3 4 5 6 7 8 9 10 11 12 1314151E-6
1E-5
1E-4
1E-3
0.01
0.1
1
10
100
1000
10000
Sky Brightness (Jy.arcsec
-2
)
Wavelength (μ )m
MK
Emission = 5% @ 0° C
Sky emission
3 4 5 6 7 8 9 10 11 12 1314151E-6
1E-5
1E-4
1E-3
0.01
0.1
1
10
100
1000
10000
Sky Brightness (Jy.arcsec
-2
)
Wavelength (μ )m
Emission = 5% @ -63° C
SP
Sky emission
3 4 5 6 7 8 9 10 11 12 1314151E-6
1E-5
1E-4
1E-3
0.01
0.1
1
10
100
1000
10000
Sky Brightness (Jy.arcsec
-2
)
Wavelength (μ )m
Emission = 5% @ -66° C
DC
3 4 5 6 7 8 9 10 11 12 131415
0.0
0.2
0.4
0.6
0.8
1.0
Transmission
Wavelength (μ )m
Sky Transmission - NIR/MIR
MK
3 4 5 6 7 8 9 10 11 12 131415
0.0
0.2
0.4
0.6
0.8
1.0
Transmission
Wavelength (μ )m
Sky Transmission - NIR/MIR
DC
Relative integration time : MK versus SP, DC, DA
3 4 5 6 7 8 9 10 11 12 13 141
10
100
1000
Relative integration time
Wavelength (μ )m
Relative integration time : 8m MK versus 2 m DC PILOT
diffraction limit
3 4 5 6 7 8 9 100.1
1
10
100
relative integration time
wafvlength
Relative integration time : 8m MK versus 2 m DC PILOT
3 4 5 6 7 8 9 100.1
1
10
100
relative integration time
wavelength
Seeing limit - extended object
Relative integration time : 8m MK versus 2 m DC PILOT
Seeing limit - extended object
v R I
J H
L
M
N
Q1 10
8
10
12
14
16
18
20
22
24
26
Limiting Magnitude
Wavelength (μ )m
extended object
K
vR
IJ
HK
L
M
N
Q
1 105
10
15
20
25
30
Limiting Magnitude
Wavelength (μ )m
-point source
Possible PILOT Instruments
Visible (AO-on) imaging:
4k array (0.03 arcsec/pixel) = 2.3 arcmin FOV
NIR wide field imaging JHK bands:
4k array (0.6 arcsec/pixel) = 10 arcmin FOV
DF imaging KLM bands:
1k array (0.23 arcsec/pixel) = 4 arcmin FOV
MIR imaging N band:
0.5k array (0.7 arcsec/pixel) = 6 arcmin FOV
V band imaging - AO on
10 100 1000
23
24
25
26
27
pilot
DC8
hstvst
jwst ??
keck
MK2m
gemini
Limiting Magnitude
FOV
0.01 0.1 1
28
29
30
31
pilot
DC8
hst
jwst ??
keck
MK2m
gemini
limiting magnitude
Resolution
10 100 1000 1000022
23
24
25
pilot
DC8
hst
vst
jwst ??
keck
MK2m
gemini
Limiting Magnitude
FOV0.01 0.1 1
22
23
24
25
pilot
DC8
hst
vst
jwst ??
keck
MK2m
gemini
limiting magnitude
Resolution
Point source
ext object
100 1000 1000019
20
21
22
23
24
pilot hst
MK2m
vista
jwstkeck
pilot2
geminiMCAO
dc8
limiting magnitudfe
FOV
K band
0.1 119
20
21
22
23
24
pilothst
MK2m
jwstkeck
pilot2
geminiMCAO
dc8
Limiting mag
Resoution
K band
100 1000 1000017
18
19
20
21
22
pilothst
MK2m
vista
jwst
keckpilot2
geminiMCAO
dc8
limiting magnitudfe
FOV
K band
K band imaging - tip tilt
0.1 117
18
19
20
21
22
pilothst
MK2m
vista
jwst
keckpilot2
geminiMCAO
dc8
Limiting mag
Resoution
K band
Point source
ext object
10 100 10006
8
10
12
14
16
pilotMK2
jwst
keckgemini
DC8
Limiting MAgntiude
FOV1 2
6
8
10
12
14
16
pilotMK2
jwst
keckgemini
DC8
Limiting magnitude
resolution arcsecs
1 26
8
10
12
14
16
pilot
MK2
jwst
keckgemini
DC8
Limiting magnitude
resolution arcsecs
10 100 10006
8
10
12
14
16
pilot
MK2
jwst
keck gemini
DC8
Limiting MAgntiude
FOV
N band imaging
Point source
ext object
Summary
• Visible AO system (40-100 actuators plus tip-tilt):
– near diff lim for on-axis stars 8-12 mag– off-axis reasonable performance up to 1-2 arcmin– highest ground based resolution!!– mirror figure error is very important < 50 nm rms required– spectroscopy?
• Near Infrared K band imaging:
– tip-tilt correction is enough for near diff lim (0.2-0.3 arcsec)– equivalent to 8m ML telescope for extended object, 5m for point source– wide field or narrow field science?
• Mid-Infrared imaging:
– niche is wide field sensitivity
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