Simulating Phase Screens

摘要

The simulation and performance evaluation of high-order, adaptive-optics (AO) corrective systems for the new, large telesocpes require the generation of distorted wavefronts (WF) that accurately model the behaivor of the real atmosphere. Roggemann et al. ~1 have introduced a method of accurately generating distorted wavefronts based on the covariance matrix of wavefrotn distortions and Cholesky factorization. Several authors have proposed fractional-Brownian-motion algorithms that are more computationally effiicent as alternatives for generating distorted wavefronts but do not give accurate correlations. In this paper, the fractional Gaussian process (FGP) algorithm is introduced as a new mehtod of generating distorted wavefronts. The algorithm is presented in both one and two dimensions. The correlation function and power spectra of simulated wavefronts are shown to compare well to the expected correlation and power spectra respectively. It is concluded that the FGP algorithm is an accurate and efficient method of generatingsimulated wavefronts.