ABSTRACT
Accurate prediction of the short-term future behavior of atmospherically distorted wave fronts would permit the elimination of delays inherent in current adaptive-optics systems. It is shown by using astronomical image data that atmospherically induced wave-front distortions as represented by time series of wave-front tips and tilts measured in the visible and piston values measured in the infrared are predictable to a degree that would be useful in an adaptive-optics system. Adaptive linear predictors as well as predictors based on the back-propagation neural network are employed in this study.
ABSTRACT
The observed motion of stellar-image centroids is shown to have a chaotic attractor with a correlation dimension of ~6. The existence of a chaotic attractor in star wander, or equivalently in wave-front tilts, indicates that the atmospheric processes that cause image degradation may be more accurately described as chaotic, not so random as is usually assumed. This new result has important implications for the accurate modeling of atmospheric processes, the operation of adaptive optics systems, and the processing of stellar images.
