Share Email Print
cover

Proceedings Paper

Optimisation of the range gating and calibration processes on the GLAS Rayleigh Laser Guide Star at the WHT
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

The Laser Guide Star commissioned in 2007 at the WHT on La Palma is based on Rayleigh backscattering of a 515 nm beam provided by a diode pumped Q-switched doubled frequency Yb:YAG laser launched from behind the WHT secondary mirror. At the time the laser beam is focused at a distance of 15km above the telescope ground and its power just under 20W. With such a pulsed laser, careful fine tuning of the range gate system is essential to isolate the most focused part of the LGS and eliminate parts of the laser plume which would degrade the Shack-Hartmann spots and consequently AO correction. This is achieved by an electro-optic shutter using Pockels cells, triggered by a delay generator synchronised on the laser pulses, and by spatial filters. Images of 0.15" resolution in J and H bands, very close to expected performance, have been routinely taken as soon as the third and fourth commissioning runs. Here we show the performance of the range gate system as measured and improved over the successive commissioning runs, as well as the off sky and on sky calibration procedures of the LGS AO system.

Paper Details

Date Published: 14 July 2008
PDF: 12 pages
Proc. SPIE 7015, Adaptive Optics Systems, 70154E (14 July 2008); doi: 10.1117/12.788774
Show Author Affiliations
Olivier Martin, Isaac Newton Group of Telescopes (Spain)
Don Carlos Abrams, Isaac Newton Group of Telescopes (Spain)
Tibor Agócs, Isaac Newton Group of Telescopes (Spain)
Chris Benn, Isaac Newton Group of Telescopes (Spain)
Craige Bevil, Isaac Newton Group of Telescopes (Spain)
Diego Cano, Isaac Newton Group of Telescopes (Spain)
Nigel Dipper, Univ. of Durham (United Kingdom)
Thomas Gregory, Isaac Newton Group of Telescopes (Spain)
Juan Carlos Guerra, Isaac Newton Group of Telescopes (Spain)
Tim Morris, Univ. of Durham (United Kingdom)
Richard Myers, Univ. of Durham (United Kingdom)
Sergio Picó, Isaac Newton Group of Telescopes (Spain)
Samantha Rix, Isaac Newton Group of Telescopes (Spain)
René Rutten, Isaac Newton Group of Telescopes (Spain)
Jure Skvarc, Isaac Newton Group of Telescopes (Spain)
Simon Tulloch, Isaac Newton Group of Telescopes (Spain)


Published in SPIE Proceedings Vol. 7015:
Adaptive Optics Systems
Norbert Hubin; Claire E. Max; Peter L. Wizinowich, Editor(s)

© SPIE. Terms of Use
Back to Top