The effect of temporal fluctuations in r_0 on high-resolution observations

摘要

Previous experimental measurements and theoretical modelling indicate that atmospheric turbulence is expected to show intermittency (or "clumpiness"). The impact that this intermittency has on simulated adaptive optics (AO) and Lucky Imaging (LI) performance is assessed in this SPIE contribution using simulated phase screens with Von Karman power spectra which incorporate turbulent intermittency. The statistics of the intermittency model used are based as closely as possible on astronomical seeing measurements at real observatories. The performance of realistic AO correction of large Taylor screens with intermittent turbulence is compared directly with the performance given with traditional Gaussian random Taylor screens having the same Von Karman power spectrum. Also discussed is the improvement in performance which can be obtained by modifying the AO control parameters in response to the changing seeing conditions. Lucky Imaging simulations indicate that the performance of this method can be significantly improved under intermittent seeing.