LGS Na spot elongation and Rayleigh scattering effects on Shack-Hartmann wavefront sensor performances

This paper describes the effects of Laser Guide Star spot elongation and Rayleigh scattering on wavefront sensing performances. An analytical model of Rayleigh scattering and a numerical model of laser plume generation at the altitude of the atmospheric sodium layer were developed. These models, integrated into a general Adaptive Optics (AO) simulation, provide information about the non-uniform centroid measurement accuracy on the sensor sub-apertures. The effects of laser power, laser type, laser launching position, sensor sampling and sensor field of view on the AO loop performances are analyzed and discussed.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.