干旱区生态环境知识资源中心

Results of numerical simulations of the performance of GLAS (Ground-layer Laser Adaptive optics System) are presented. GLAS uses a Rayleigh laser guide star (LGS) created at a nominal distance of 20km from the 4.2m William Herschel Telescope primary aperture and a semi-analytical model has been used to determine the observed LGS properties. GLAS is primarily intended for use with the OASIS spectrograph working at visible wavelengths although a wider-field IR imaging camera can also use the AO corrected output. Image quality metrics relating to scientific performance for each instrument are used showing that the energy inside every OASIS lenslet across the 10" instrument FOV is approximately doubled, irrespective of atmospheric conditions or wavelength of observation.