The standard adaptive optics system can be viewed as a sampled-data feedback system with a continuous-time disturbance (the incident wavefront from the observed object) and discrete-time measurement noise. A common measure of the performance of adaptive optics systems is the time average of the pupil variance of the residual wavefront. This performance can be related to that of a discrete-time system obtained by lifting the incident and residual wavefronts. The corresponding discrete-time model is derived, and the computation of the adaptive optics system residual variance is based on that model. The predicted variance of a single mode of an adaptive optics system is shown to be the same as that obtained via simulation (as expected). The discrete-time prediction is also shown to be superior to a continuous-time approximation of the adaptive optics system.
© 2007 Optical Society of America
Atmospheric and oceanic optics
Original Manuscript: January 10, 2007
Manuscript Accepted: April 13, 2007
Published: August 14, 2007
Douglas P. Looze, "Discrete-time model of an adaptive optics system," J. Opt. Soc. Am. A 24, 2850-2863 (2007)