Possibilities of adaptive optical correction of the global wavefront tilt using signals from traditional and polychromatic laser guide stars
L.A. Bolbasova, V.P. Lukin
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: laser guide star, adaptive optics, atmospheric turbulence
Abstract
The work is devoted to the application of laser guide stars (LGS) technology for the adaptive optics system of a ground-based telescope. The results of the study of the possibilities of correcting the global wavefront tilt with the use of LGS are presented. To approaches are compared: polychromatic LGS, where the correction signal is a difference random refraction due to the atmosphere for different optical radiation wavelengths, and traditional monochromatic LGS, where an LGS is considered as a point source with a random center. The calculations were performed in the approximation of the Huygens-Fresnel method. It is shown that in this approximation, the signal from a monostatic monochromatic LGS used to correct the global wavefront tilt is comparable to the signal from a polychromatic LGS. Seasonal changes in the concentration and altitude of the mesospheric sodium layer, which determines the characteristics of sodium LGS, are estimated for Russian observatories.
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