Title: PILOT: Pathfinder for an International Large Optical Telescope -performance specifications
1PILOTPathfinder for an International Large
OpticalTelescope-performance specifications
Jon Lawrence
JACARA Science Meeting PILOT Friday March
26 Anglo Australian Observatory
2The data
DOME C
South Pole
- 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
3Seeing 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)
4Seeing Data Dome C - 2003/4
- DIMM summer 2003/4
- data not yet reduced
- median seeing lt 1.1 arcsec (0.4-0.7 arcsec)
- isoplanatic angle 10 arcsec
5CN2 profile Dome C Bad
?iso 9.5 arcsec fG 30 Hz
?iso 13.5 arcsec fG 7 Hz
r0 0.05 m (1.8 arcsec seeing)
r0 0.2 m (0.5 arcsec seeing)
6CN2 profile Dome C Good
?iso 9.5 arcsec fG 30 Hz
?iso 13.5 arcsec fG 7 Hz
?iso 30 arcsec fG 2Hz
r0 0.05 m (1.8 arcsec seeing)
r0 0.2 m (0.5 arcsec seeing)
r0 0.7 m (0.15 arcsec seeing)
7CN2 profile Mauna Kea
?iso 9.5 arcsec fG 30 Hz
?iso 13.5 arcsec fG 7 Hz
?iso 30 arcsec fG 2Hz
?iso 2 arcsec fG 50 Hz
r0 0.05 m (1.8 arcsec seeing)
r0 0.2 m (0.50 arcsec seeing)
r0 0.7 m (0.15 arcsec seeing)
r0 0.20 m (0.50 arcsec seeing)
8Atmospheric 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
9Atmospheric 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
?
?
10Adaptive Optics
object
guide star
to tip-tilt secondary
tip-tilt control
telescope optics
centroid sensor
dichroic beam splitters
deformable mirror
image camera
wavefront control
wavefront sensor
wavefront analysis
11PILOT AO systems
- Tip-tilt
- tip-tilt mirror quad sensor
- Low Order AO
- ds0.3 (30-50 actuators)
- High Order AO
- ds0.08 (500-1000 actuators)
12PILOT 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
13Strehl ratio - V band
On-axis low order
DCG
DCB
MK
14Strehl Ratio
15Strehl ratio - K band (tip-tilt correction)
Off-axis
On-axis
DCG
DCG
DCB
DCB
16Uncomp DCB
Uncomp DCG
Diff lim 2m
17Uncomp DCB
Uncomp DCG
DCB off-axis
DCG off-axis
Diff lim 2m
on-axis
18Uncomp DCB
Uncomp MK
Uncomp DCG
DCB off-axis
DCG off-axis
Gemini altair
Diff lim 8 m
Diff lim 2m
on-axis
19(No Transcript)
20Sky emission
MK
Emission 5 _at_ 0 C
21Sky emission
SP
Emission 5 _at_ -63 C
22Sky emission
DC
Emission 5 _at_ -66 C
23Sky Transmission - NIR/MIR
MK
24Sky Transmission - NIR/MIR
DC
25Relative integration time MK versus SP, DC, DA
26Relative integration time 8m MK versus 2 m DC
PILOT
diffraction limit
27Relative integration time 8m MK versus 2 m DC
PILOT
Seeing limit - extended object
28Relative integration time 8m MK versus 2 m DC
PILOT
Seeing limit - extended object
29Possible 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
30V band imaging - AO on
Point source
ext object
31Point source
K band imaging - tip tilt
ext object
32Point source
N band imaging
ext object
33Summary
- 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 lt 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