Title: High-Resolution Altitude Profiles of the Atmospheric Turbulence with PML at the Sutherland Observatory,
Abstract: With the prospect of the next generation of ground-based telescopes, the
extremely large telescopes (ELTs), increasingly complex and demanding adaptive
optics (AO) systems are needed. This is to compensate for image distortion
caused by atmospheric turbulence and fully take advantage of mirrors with
diameters of 30 to 40 m. This requires a more precise characterization of the
turbulence. The PML (Profiler of Moon Limb) was developed within this context.
The PML aims to provide high-resolution altitude profiles of the turbulence
using differential measurements of the Moon limb position to calculate the
transverse spatio-angular covariance of the Angle of Arrival fluctuations. The
covariance of differential image motion for different separation angles is
sensitive to the altitude distribution of the seeing. The use of the continuous
Moon limb provides a large number of separation angles allowing for the
high-resolution altitude of the profiles. The method is presented and tested
with simulated data. Moreover a PML instrument was deployed at the Sutherland
Observatory in South Africa in August 2011. We present here the results of this
measurement campaign.