Translator Disclaimer
17 October 1997 Subpupil estimation of the laser guide star tilt term
Author Affiliations +
We present a new technique aimed to obtain the downward tilt of a Laser Guide Star (LGS). The concept of this technique consists in averaging the LGS tilt signals as seen from many non-contiguous sub-pupils located on the telescope aperture. The sub-pupils tilt signals have two different contributions. One, common to all the various subpupils, is due to the upward beam propagation, the other, different on the various sub-pupils, is due to the downward beam propagation. These downward tilts have a correlation degree dependent on the sub-pupils array geometry and on the value of outer scale of turbulence. Summing up the sub-pupil signals allows to average out the tilt signal component due to the beacon downward propagation, so obtaining an estimation of the upward propagation laser beam tilt. We show here the achievable results in terms of the ratio between residual tip-tilt error variance obtained using this technique and the uncorrected tip-tilt variance. In particular the dependence from outer scale of turbulence and the use of multi-telescope systems are investigated.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Armando Riccardi, Simone Esposito, and Roberto Ragazzoni "Subpupil estimation of the laser guide star tilt term", Proc. SPIE 3126, Adaptive Optics and Applications, (17 October 1997);


The Euro50 extremely large telescope
Proceedings of SPIE (January 30 2003)
Control challenges for extremely large telescopes
Proceedings of SPIE (August 14 2003)
Laser guide star projection for large telescopes
Proceedings of SPIE (June 28 2006)
The aggregate behavior of branch points a proposal for...
Proceedings of SPIE (August 12 2010)

Back to Top