Experimental verification of the frozen flow atmospheric turbulence assumption with use of astronomical adaptive optics telemetry.
We use closed-loop deformable mirror telemetry from Altair and Keck adaptive optics (AO) to determine whether atmospheric turbulence follows the frozen flow hypothesis. Using telemetry from AO systems, our algorithms (based on the predictive Fourier control framework) detect frozen flow >94% of the time. Usually one to three layers are detected. Between 20% and 40% of the total controllable phase power is due to frozen flow. Velocity vector RMS variability is less than 0.5 m/s (per axis) on 10-s intervals, indicating that the atmosphere is stable enough for predictive control to measure and adapt to prevailing atmospheric conditions before they change.
Poyneer
Lisa
L
Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA. poyneer1@llnl.gov
van Dam
Marcos
M
Véran
Jean-Pierre
JP