Category: MAPS

We made a lot of AO progress tonight! We switched over to the VisWFS and CACAO, and started with measuring latency (mlat). Jared and Olivier joined us on Zoom and helped debug some settings that were causing us to think our hardware latency was noisy and to suspect timing issues or simlinking the slopes instead of the pupils, but now we think it was actually just a normalization. Here is a nice mlat we got:

After the mlat’s, we closed the loop on the first 3 modes with our best response matrix from March. It worked!! But we couldn’t do higher-order modes — probably because the pupil and alignments had changed. So we moved on to take a new response matrix, but closing on the first 3 modes using the March matrix. We also tested tip/tilt offloading to the mount. And after some investigation of why some of the modes looked noisy or didn’t have much power in them via plotting self response matrices (selfRM), we continued and took a 50-modes calibration. We closed the loop with it and (even though we had to put tiny gains on modes 37-50), it was actually correcting and improved the PSF!

It was cloudy this afternoon and there were a few patchy clouds at sunset, but pretty soon it cleared up and we had a nice night with seeing around 1-1.3”. Earlier in the day Jarron opened the warmed-up BLINC and removed the baffle that was vignetting his pupil, so tonight we all had good pupils for the first time and we were able to get some nice looking PSFs!

When Jared and Olivier went to bed it was time to end our time with CACAO for tonight, and switch to Jacob and Suresh’s project with DO-CRIME and the IR WFS. We finally ended at dawn, a very full and useful night!

The best 15 minutes of the day were trying to watch the green flash at sunset with Amali, Lauren, and Bianca. (We didn’t see it though, but we used the trick Gill taught us.)

The song of the night is “Toxic” by Britney Spears (2004)

The nice thing about observing at the MMT rather than Magellan (even though they don’t haul food, meal prep, cook, nor clean dishes for us here) is that when you have an urgent need for one of your engineers to come up, it’s only a 2-hour drive (rather than a 2-day flight/drive) from Tucson! Tonight Grant kindly came up and got us aligned.

Why did we need to do alignment again? Well between the telescope and the AO bench we have so many degrees of freedom, and the telescope staff that we work with have different ideas about what to do, and our team has different ideas about what to do, that we had gotten very misaligned and had to start all over again. As I mentioned yesterday, Tim and Ben got us aligned to the chief ray of the telescope. Tonight Grant, Oli (remotely), Bianca, Manny, et al then went back to our first upstream optic: the dichroic — and starting there did a beautiful iterative alignment (even having to move the MOUNT of periscope 1 because it had run out of range) and got us filled pupils! (Especially after Amali also encouraged some of the edge actuators to do a better job holding up their edges.)

Yes we are still a bit unclear as to why the dichroic was so far off (since we hadn’t touched it and we THOUGHT we were on the chief ray in January when we installed/aligned it), and why periscope 1 had wandered so far. But I think it’s just a complex system with many parts controlled by different teams and we have different staff (both from MMTO and MAPS) at different times so we never quite know if we are doing things the same way every time, no matter how hard we try, especially since the system is still so new and we are constanly making adjustments and working out kinks anyway.

So we will continue to learn more about the situation, but thanks to Grant for coming up and Oli for being on the phone and to everyone for filling our pupils once again!

After this we went on-sky and Andrew got the IR CTL pupil tracking working! And then Jacob and Suresh took Do-Crimes interaction matrices and closed the loop with a 20-modes loop! We were debugging this at dawn when some patchy clouds suddenly showed up (after a beautiful clear night with 0.8-1” seeing) and so it was time to call it a night (It’s a night!).

The best 15 minutes of the day were one of my trips up to see the alignment in the dome.

Song of the night: “I’m a Slave 4 U” by Britney Spears (2001)

Conditions were great tonight — clear, not too windy, and seeing around 0.8” (definitely usable).

Also I updated yesterday’s post with some pictures and a song of the day.

Tonight was the second MIRAC night and the instrument had finished cooling and was nice and cold, so Jarron got to taking data! Unfortunately he had a vignetted pupil again (but differently from last time) but he still got a lot of good throughput and sensitivity measurements.

Meanwhile on the AO side we worked on trying to align our vignetted pupil with the periscope, and also tested the IR camera lens, and took data to calibrate the IR camera lens loop.

Also we spent some time with MMTO staff (Ben and Tim) in the first half working on getting the hexapod offsets to point to the rotational center of the telescope. This involved rotating the instrument rotator, measuring the arc on MIRAC, and shifting the hexapod to point there.

By the way, I forgot to mention that we also found ASM contamination yesterday. It was a hard blockage about 160 microns tall. After the contamination removal procedure by Manny, Amali, and Dan, it got down to 60-80 microns, which was workable.

The best 15 minutes of the day were when, after I woke up early (around 7am), I was reading and grew sleepy again, and realized I was about to get my second sleep! Very important for successfully shifting to a night schedule!

Song of the night: “Oops I Did It Again” by Britney Spears (2000)

The first two nights of this run are for MIRAC (PI: Leisenring), while the last 4 are for AO (PI: Morzinski). Therefore I decided this was my chance to come up in the morning to see the installation of MAPS. See, usually I try and sleep in on the morning before a MAPS run, to help me switch to a night schedule. But instead today I got up in the morning as usual, headed up to MMT, and was able to observe the installation of the Top Box and ASM with a full MMTO crew as well as Dan and Ruby from MAPS. This is important to me because we’ve talked a lot about the installation procedure and whether it can be made more repeatable, but I hadn’t actually seen the full procedure yet. Now I have a much better picture of the process and thoughts about repeatability.

So here’s what I saw. When the Top Box is installed there are 4 feet on the lift that can be independently adjusted. However, the actual measurement of how parallel the Top Box plate is to the Cass plate is through hand-held measuring tapes. There are 2 pins that help guide the Top Box up. And in the end the plates were flush. But I was wondering whether there could be any skew on one side or another.

The ASM installation is complex. The ASM is mounted to the hexapod. This is done while the former is hanging from the crane and the latter is supported on a bouncy stand — so could these be misaligned? But then the screws are gronked on until the plates are flush, except for a gap covering about 20deg on one side where the ASM plate is warped, of about 4 thou. Then the hexapod is mounted to the hub. It’s behind a flange, but the 2 pins keep it aligned, one of them is diamond shaped to control angle, and then the screws are gronked on until tight so we assume it is flush too.

Also Dan and Ruby connected the rack and all our other cables:

Then tonight was supposed to be a MIRAC night but they had a chiller problem and weren’t cold enough, so instead we decided to try AO.

Except instead it still took over half the night to complete set-up and alignment. So we continue to explore how to improve these procedures.

Even though this is the MAPS run not the MagAO-X run, I’ll stick with the MagAO-X blog rules for this run. Therefore, the best 15 minutes of the day were seeing the ASM mount to the Hexapod and then the whole assembly mount to the Hub. I have to admit I’ve never quite pictured it correctly when we talk about in our off-mountain meetings, so this helped me visualize what’s happening very well!

Song of the Day/Night: “…Baby One More Time” by Britney Spears (1998)