Category: MagAO-C

We (Laird, Jared, Katie, Alfio, Armando, Marco, Runa, Enrico, Simone, Luca, Carmelo, and Alessandro) have been working hard all week here at Arcetri to prepare for the Pre-Ship Review.

For today’s installment we have a video of the VisAO PSF as we test closing the loop and adjusting the gains.  Laird is narrating and Katie is operating MagAO in this clip. 

Descripion of video:  The Magellan AO system loop closing and opening at 1kHz on an 8.5-mag guide star in 0.8” seeing with 33 mph (15 m/s) wind. The image viewer is showing our SDSS i’ PSF, and we have selected a 32×32 subwindow of the CCD 47 (our VisAO science detector) to operate at 42 frames per second. You can see the impact on Strehl ratio (calculated from slope telemetry) and FWHM (fitting the PSF in real time) when the loop gains are low.

First we see the closed-loop PSF.  Then the loop is opened.  When we close the loop, we start with low gain and slowly ramp up first the low-order gain and then the high-order gain.  MagAO is operated with modal gains so that each mode (up to 400 controllable modes) can be operated with its own gain.  The automated gain algorithm searches for the best gain for each mode that minimizes the WFE.  However, gain can also be adjusted by hand, in groupings of low-order (tip/tilt), mid-frequencies, and high-order (above 100 modes for bin 1).

Due to the always too short amount of time we get to spend with our instrument here, we work some long hours. Late at night and on weekends the front gate to Arcetri is closed, so we have to go around the back way. It is actually a nice walk, and we discovered the last remaining snow in Florence. In the picture you can see the top of the Solar Tower, where our adaptive secondary mirror is mounted. It is performing very well, and we are putting the last touches on the amazing automation that was developed here at Arcetri.

Laird, Jared, and Katie (new postdoc) arrived yesterday for prep work and then for the Pre-Ship Review that will happen on the 23rd-24th Feb.  Katie is getting up to speed on MagAO while Laird and Jared verify that the system still performs as it did last Nov/Dec.  It’s chilly in Florence and we are running tests such as starting up the system, homing the motors, etc.  We are also setting up the Chem. Lab. as the “Control Room” via ethernet link (and radio for voice) in order to be able to demonstrate remote ops. during the review.  We warmed up the bench and got the system up and running, and will close the loop tomorrow.

The MagAO team (or at least part of it) has returned to Florence for another round of integration and testing. I (Jared) have been here for 2 weeks, and Laird and Derek just arrived. As soon as I arrived we successfully closed the loop again, with only minimal adjustments of the alignment using the X-Y-Z stages. The system came right back up, with less than 5 minutes of work, after 3 months of down time.

The last two weeks have been mostly uneventful, consisting of a lot of software development and debugging. In preparation for the next 2 weeks of work on the ASM and the CRO tests we removed the NAS from the tower on Friday. The two videos below show the process of lowering, and then tilting the NAS upright on its handling cart.

While the NAS is off the tower we will be fine tuning the WFS and VisAO camera alignment, as well as testing the AO to Magellan software interface. In about two weeks we’ll reverse the process, and mount everything back in the tower for some more exciting closed loop action.