Starting on Oct 13, three days of intense work were spent installing, testing and tuning the various reconstructors prepared in Arcetri by our Italian colleagues, and computing interaction matrices... A mask was also installed, as planned, on the thin shell central hole dust cover to hide the mouse hole.
The dust cover before the installation of the mask. The mouse hole is seen on the left of the cover
The mask is now clamped on the dust cover, covering the mouse hole
On Sep 15, day-time results looked very promising and the team went to the sky for nearly two hours of clear weather before observations had to stop for high humidity for the rest of the night. The new reconstructor slaving all actuators of the internal ring was used on a Rmag = 6.7 with seeing values in a range from 1.0 to 1.8 arcseconds. Correcting for 400 modes yielded the image below. The strehl ratio in H is 87%.
The good news is that the modal basis, optical masking, and WFS digital masking introduced in the new AO software are able to deal with the warping of TS4 in the central region.
More tests to come, weather permitting!
R. Briguglio, L. Busoni, S. Esposito, A.Puglisi (Arcetri), J.C Guerra and J. Christou (LBTO) are the actors on the Mt Graham