Advanced Adaptive Correction of Turbulent Distortions Based on a Shack-Hartmann Wavefront Sensor Measurements
L. B. Antoshkin, V. V. Lavrinov, L. N. Lavrinova
Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences
lnl@iao.ru
Keywords: prediction, centroid coordinates, frozen turbulence time, transverse wind speed, random phase screen, differential method, wavefront sensor
Pages: 92-102
Abstract
The propagation of laser radiation through the atmosphere is accompanied by a change in the light field under the influence of turbulence and is a random process. An adaptive system that includes a Shack-Hartmann wavefront sensor and a flexible mirror corrects distortions found at the previous time but changed before being corrected by the system. Analysis of turbulence within a given time period allows one to predict turbulent distortions at the subsequent time and use it to make a correction in the radiation phase distribution. The adaptive correction performance can also be improved by preparing the reflective surface of the adaptive mirror based on predictions of the state of the wavefront at the next time by the turbulence parameters and the transverse component of the wind speed found in previous Hartmann-Shack sensor measurements.
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