Angular anisoplanatism in laser guide star adaptive optics

摘要: The image quality obtained using laser guide star adaptive optics (LGS AO) is degraded by the fact that the wavefront aberrations experienced by light from the LGS and from the science object differ. In this paper we derive an analytic expression for the variance of the difference between the two wavefronts as a function of angular distance between the LGS and the science object. This error is a combination of focal anisoplanatism and angular anisoplanatism. We show that the wavefront error introduced by observing a science object displaced from the guide star is smaller for LGS AO systems than for natural guide star AO systems.