Study On Adaptive Optical Wavefront Reconstruction Algorithm

The atmospheric turbulence influence to beam of light could been compensated by adaptive optical system. And so the angular resolution approach or attain the diffraction limit. How to do wavefront reconstruction and correction more rapidly and precisely were not only the key part of the adaptive optical system but also the difficult part of the digital signal processing.In this thesis, the statistic characteristics of optical wavefront phase infulenced by atmos -phere turbulence were presented, and four simulation methods were discussed, including Karhunen-Loeve function based on Zernike polynomials, wavelets transform, Fourier trans -form and ARMA method. Their precision and simulation-velocity were compared, as a result, it's shown that the first two were better than the other.Then, the wavefront reconstruction algoritlim was discussed in detail. Firstly, the basical principle of Hatmann-Shack sensors data collection and data processing were provided. Second -ly, the linear modal of wavefront reconstruction and correction in adaptive optical systems were discussed, including Least-Square (LS) and Least-Mean-Square (LMS). And then four kinds of sloving algorithm were discussed in detail. Finally those algorithm were compared through number simulations. A synthesis algorithm bsaed on BIGSTAB, with precondiction technology and Multigrid method were provided to slove those high dimension, high sparse and singular equation. And also, performance of LS and LMS were compared in different signal noise rate condition, it's shown that BICGSATB algorithm had higher speed than SVD algorithm, which was used widely by now, but had the same precision as SVD, especially when equation has high dimension.