Tackling down the low wind effect on SPHERE instrument
Creators
- Sauvage, Jean François1
- Fusco, Thierry1
- Lamb, Masen2
-
Girard, Julien3
- Brinkmann, Martin3
- Guesalaga, Andres4
-
Wizinowich, Peter5
- O'Neal, Jared3
-
N'Diaye, Mamadou6
-
Vigan, Arthur7
- Mouillet, David
- Beuzit, Jean-Luc8
- Kasper, Markus3
- Le Louarn, Miska3
-
Milli, Julien3
- Dohlen, Kjetil7
- Neichel, Benoît7
- Bourget, Pierre3
- Haguenauer, Pierre3
-
Mawet, Dimitri9
-
1.
Office National d'Études et de Recherches Aérospatiales
-
2.
University of Victoria
-
3.
European Southern Observatory
-
4.
Pontificia Universidad Católica de Chile
-
5.
W.M. Keck Observatory
-
6.
Space Telescope Science Institute
-
7.
French National Centre for Scientific Research
-
8.
Institut National des Sciences de l'Univers
-
9.
Jet Propulsion Lab
Contributors
Abstract
SPHERE is the VLT second generation planet hunter instrument. Installed since May 2014 on UT3, the system has been commissioned and verified for more than one year now and routinely delivers unprecedented images of star surroundings, exoplanets and dust disks. The exceptional performance required for this kind of observation makes the appointment: a repeatable Strehl Ratio of 90% in H band, a rough contrast level of 10-5@0.5 arcsec, and reaches 10-6 at the same separation after differential imaging (SDI, ADI). The instrument also presents high contrast levels in the visible and an unprecedented 17mas diffraction-limited resolution at 0.65 microns wavelength. SAXO is the SPHERE XAO system, allowing the system to reach its final detectivity. Its high performance and therefore highly sensitive capacities turns a new eye on telescope environment. Even if XAO performance are reached as expected, some unexpected limitations are here described and a first work around is proposed and discussed. Spatial limitation: wave-front aberrations have been identified, deviating from kolmogorov statistics, and therefore not easily seen and compensated for by the XAO system. The impact of this limitations results in a degraded performance in some particular low wind conditions. Solutions are developed and tested on sky to propose a new operation procedure reducing this limitation. Temporal limitation: high amplitude vibrations on the low order modes have been issued, due to telescope environment and XAO behaviour. Again, a solution is developed and an assessment of its performance is dressed. The potential application of these solutions to E-ELT is proposed.
Additional Information
© 2016 Society of Photo-Optical Instrumentation Engineers (SPIE).Attached Files
Published - 990916.pdf
Files
990916.pdf
Additional details
Identifiers
- Eprint ID
- 87169
- Resolver ID
- CaltechAUTHORS:20180615-154904987
Dates
- Created
-
2018-06-18Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field
Caltech Custom Metadata
- Series Name
- Proceedings of SPIE
- Series Volume or Issue Number
- 9909