Blog – Page 21 – Extreme Wavefront Control Lab

MAPS May 2024A Night 4: CACAO 50

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:

Screen grab of the AO control computer while taking hardware latency (mlat) measurements. Top left is the pyramid pupils, small plot to its right are the slopes, medium plot to its right is the DM display, terminals in upper right corner are CACAO, ASM GUI is in lower left, gain GUI is in lower right, and the gnu plot at center bottom is the mlat result: The purple curve is from earlier in the night before restarting CACAO and getting rid of our settings, and the green curve is the new mlat result after debugging the noise/timing/simlinks/settings.

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)

MagAO-X 2024Ab Day 11: Cloudy but fun week

There were new faces this time so I am going to introduce myself. I am Carla the youngest Magellan operator eh eh. For now at least.

My week with you guys started on Monday, when I realized you are at the mountain and thinking about the treat I am going to get you this time. So, just before going to El Pino I brought a couple of “dulces chilenos”. I see you like the alfajores and that’s a very typical Chilean dessert filled with the best sweet of all, manjar.

It was a week where we were closed almost all the time, the telescope was open only 22 hours! So that’s kind of a record for me. But it was a great opportunity for me to spend time with you and laugh at your very funny way of being. I appreciate your spirits.

This time I tried an artistic empanada day photo.

Actually tonight you get the famous picture with the 6.5mts mirror, and I have to admit I can’t believe you didn’t have it before, so it was good. You have the best poses, so of course I copy one of them and get my own picture, thank you eh eh.

Then, we saw the auxiliar building where the mirror is aluminized and got the other instruments ready. It was fun to have this tour. We can repeat these pictures in the future with the other part of the team of course, if the weather allows us.

I get to know better about the work individually you are doing here, so for me it was a very informative week, and I want to congratulate all of you for your amazing and dazzling job you are doing for astronomy. Thank you very much for sharing this with me, you blow my mind.

I hope you have a good rest of the run and take good care of yourselves, especially on the cold nights that are coming.

My favorite 15 minutes of the week was going downstairs and tasting all of the new candy. My favorite was the chocolate eggs and the ones I couldn’t even try were the wasabi ones. I hope to bring you the real merkén next time.

The Song of the Day

A very old song but it is a good opportunity for you to get to know the great Cecilia, also it’s a song that will cheer you up during this very cloudy night.

MAPS May 2024A Night 3: Alignment Crimes

Cell phone photo (!) by Suresh of the Milky Way over the MMTO last night. [Image description: a star-filled sky, and a cloudy-looking galaxy band, over a telescope dome on top of a pine-forested mountain.]

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!

Grant looking at pyramid pupils on a laptop at the Cass of MMT in the dark. [Image description: Grant is peering at the pupil image, and about to reach in and adjust another optic and watch the change.]

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!).

Amali’s completed Tunisian crochet project! [Image description: A scarf is draped across 2 chairs. The scarf has a geometric pattern that morphs into the word “MAPS” and has colors of dark blue, reddish-orange, and whitish-cream.]

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)

MagAO-X 2024Ab Day 10: “30+ years of speckle”

This week could have gone better: Delayed and missed flights, fog, clouds, bad seeing, and I got a head cold. New at LCO this trip: no Covid test on arrival. In case you’re wondering, I brought my own, and I don’t have Covid.

Last night, I turned the super fancy MagAO-X system with its three deformable mirrors into a very expensive speckle camera. 30 years ago, when AO was in its infancy, I did my PhD thesis taking short exposures to “freeze” the seeing and a lot of Fourier transforms to recover high spatial resolution images. Well, in 1.3″ seeing, MagAO-X could still do some correction (miraculously) and the EM-CCDs in MagAO-X can run fast (I ran at about 60 ms, which is considerably longer than the normal coherence time at visible wavelengths). I can play some of those old speckle imaging tricks on images like this:

See the binary star? Of course you do. I select the best of the tens of thousands of images I took and average them up. Combined with other data I have, these images will let us measure masses of the stars.

Tonight, however, the seeing is finally down to median LCO conditions and the forecasted clouds have not yet arrives, so MagAO-X is weeping tears of joy:

A saturated PSF with all those Airy rings!

I may be bummed about the weather, but it’s been fun to be back here and collaborating with the ever-growing team. People are working shifts, so we didn’t get a photo of everyone, but here’s an obligatory sunset selfie with clear skies above.

And, dear reader, as a devoted blog follower you undoubtedly know that as predictably as the approach of winter brings clouds, Sunday brings:

I saw a fox today too, but sorry, I didn’t get a picture.

Today’s best 15 minutes were spent finishing the Sunday NYTimes Crossword Puzzle with the band of Js (Joseph, Jay, and Josh) as we froze speckles.

Song of the Day

I almost went with Lady Sings the Blues, one of my favorites for bad observing weather combined with colds, but I don’t want to be a downer. So, I’m going with Freeze Tag by Suzanne Vega in honor of those fast images we took and the coming week’s temperature forecast.

The sun is fading fast
Upon the slides into the past…

MAPS May 2024A Night 2: MIRAC

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.

Here’s our vignetted AO pupil. [Image description: Two monitors with instrument displays and GUIs. Top left camera display shows the ZWO image. A crescent pupil can be seen. It should look like the telescope pupil.]

This one is a little better. The pupil image looks mostly like the telescope pupil! [Image description: Same monitors, GUIs, and image displays. The top left display shows a mostly-filled pupil image. To the right of it is a bright blob which is the star in the focal plane. Peeking in on the right is a third monitor where you can just see the pyramid pupils — 4 pupil images instead of just 1.]

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.

ASM display, after Amali flipped it so that it matches the coordinates when you’re up on the scissor lift facing the ASM. Contamination is at 5:00. [Image description: 3 circles (the ASM at different measurements) with 336 little circles (the actuators) of different colors to represent the actuator currents, heights, and temperatures. A slight raised color table in an almost pie-shaped wedge at 5:00 is the contamination.]

Manny, Dan, and Amali removing contamination in the ASM yesterday.

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)