https://summit-lsp.lsst.codes/chronograf/sources/1/dashboards/65?refresh=Paused&lower=now%28%29%20-%2015m

2024 May 13

We looked at images (307-316) and we needed threshold of 500, box size of 100 to work.

For images 317-416:

Elana code is finding all four beams and nothing else in every image so far, and is able to centroid the beams!! Exciting. we are taking more data. One of the PSFs is garbage, but we will try convolving and see where that gets us.

Questions:

• what in the heck was happening with the focus and PSFs earlier?
  • ATMCS cRIO needed resetting? down
  • maybe primary not supported on pneumatics
    • still not understanding this - with no pneumatics maybe motion, but also short time scale
• next steps:
  • measure/calculate/compare the distances between beam centers
  • take as much data as humanly possible (in progress)
  • separate notebooks for quick look and full blown analysis (easy!)
  • making whole system remote
  • do while observing (depends on clouds)
• power law convolving with data analysis on fourth peak?
• why is PSF of fourth beam bad (beam closest to beam expander)? 
  • meghan hypothesis that maybe has something to do with light being clipped by edge of mirror
    
    

difference between dome azimuth and telescope azimuth

→ what would it take to re-acquire from scratch (meaning 

sine convention

check rotator angle post resets, plot as a function of time (look for glitches)

plot flux!!

• frame of the dome analysis
• sine conventions piezos
• plot flux

consistency with relative flux: dewar window and dome rattling (and maybe some beam blocking)

checklist:

• startup
• align
• find beams
• drive beams to desired generation
• second generation of coolness

System is basically working. Four spots on LATISS sensor with around 3 arcsec FWHM. 

What PSF do we expect? Beam is about 40mm in diameter. Diffraction limit would be 1.2 * lambda/D ~ 0.5E-6/40E-3 = 3 arcsec. 
We're close to that now. Clear diffraction rings around main sources 20240510 seq 52: 

Initial Jupyter analysis notebook is in github repository https://github.com/stubbslab/MOSS 

Here is azimuth configuration that placed beam onto detector: 

Assuming our azimuth convention is zero at N and increasing to the East, then dome slit is pointing roughly North and telescope roughly East. 
Compass check in dome has slit pointing to az~45 and telescope at 82 deg. So telescope seems OK but dome zero in azimuth seems way off. 

Dome Closed Initial Differential Motion Analysis (images 317-327 from 20240513)

Dome Open Analysis (images 1757-1767 from 20240513)

Dome Open II (images 2525-2535 from 20240513)

Discussion with Chris, Elana, Chuck (significant scope creep)

• Chuck: stratification in the dome, eddy currents, then an initial flushing when the dome is open, and then return to equilibrium after the dome open for a while (for LHS plots with elongation)
• Chris: magnitude of separation between pairs does matter DIMSUM - correlation length
• Misleading by centroiding errors?
• turn into lockin if you pulse the laser at 20 Hz = strobe coherent oscillation
  • integrated strobed camera
  • camera (readout time) as low pass filter after mixer
    • high freq components will be superimposed on low frequencies?
    • nyquist sampling frequency wraps signals
    • base band = things you can nyquist sample at the frame rate of the camera
    • drive with square wave or pulse?
      • no intensity issues - mean intensity is always the same over frequency
  • will work on frequencies up to twice the pulse duration → characterize the turbulence up to a kHz
  • speed of sweeping is limited by camera frame rate
    • exposure time * frequency repetitions on a single camera readout
    • assume frozen turbulence per pulse 
    • chris: this only allows searching for coherent components
      • if q (>= exposure time*frequency)  high enough that it's the same phase when strobed, get rid of differential motion
      • move away from that frequency - beat frequency
• what experiments can we do to inform the next generation of this device
• shutter open/closed synchronization?
  • listen to the shutter with a microphone
  • Chuck has an electrical interrupt solution
  • supposed to be a published event for both auxtel and main dome

Todos:

• block beams
  • repoint at same angle
  • block one at a time
• remote operations
• shorten pulse to surpress dome movement (chuck thinks this is miniscule)
• dome testing
• frame of the dome analysis
• square the axes on the first plots - and test that the line is at the elevation angle 
  • this would be a good confirmation - centroiding errors cannot know the dome angle
• check that no differential image motion with 10s image?
  • measure standard deviation as a function of pulse duration - coherence time of turbulence in the dome; change in characteristic time with dome open, dome closed? 
• align spots for stuttered imaging mode at current frame rate

Pulse Length/ND Filter Discussion

Chris ran reductions blindly without looking at plots. We should all reference observing logs to get a feel for PSFs or plot a few before proceeding with full analysis on plots.

Notes

• short pulses seem completely dominated by some artifact
• chris guess: laser diode turns on, heats up the second is energized
  • some thermal transient that makes emitted beam profile different for super short pulses
  • for short pulses, beam coming out of laser diode has more divergence (we don't seem to have collimated beam in this case)
  • beam expander collimation for beam on longer time scale
• we should go to the shortest beam possible that gives us good PSFs

Todos

• relevant PSFs as a function of pulse duration - plot next to each other
• go to OD 1.5, take more .1ms images to make sure PSFs/FWHM still good and we get pixel max values of 10x

Data Reduction Standards

Reduction is saved under date folder in all_peaks_df in data in MOSS repository.

There are columns in the data frame with dome status, OD filter, convolution sigma, box size, and threshold, as well as date and image numbers.

5.14 Analysis Notes

Image numbers in chart, 25 from each. We are planning to compare these. Green when all_peaks dataframe has been saved. Using conv_sigma = 35.

5.15 Analysis

Ran through images on MOSS - getting standard deviation of 400 in y direction for 3970 stack. 

• Running more images now to see if this is just the stack I pulled
• had to switch to sorting in y in the function
• Elana suggested outlier rejection - discuss further

Interpretation

Information about rot_pa in the header: https://ts-observatory-control.lsst.io/user-guide/tcs-user-guide-generic.html#rotator-position-and-sky-position-angle

MOSS On-Sky Observation Plans

Goal: without moving the dome, alternate between taking g-band on-sky images at a wide range of airmasses and 

1. run ATpneumatics_checkout
2. open dome: auxtel/atdome/open_dome.py
3. open mirror covers (component: ATPneumatics, cmd: openM1Cover)
4. enable corrections:
   1. 
5. With run command, disable dome following.
   1. 
6. run correct pointing (put range for target there)
7. try to run latiss_wep_align to focus telescope - may not work, may have to do manual focus sweep
8. NOTE: FIND CORRECT AZ POINTING FOR THE DOME
9. Find targets of mag 12 +/- 1 at a large range of airmasses/elevations and take images of those without moving dome
   1. 
   2. take_image_latiss as engtest → with g band in filter wheel, reason is on-sky, probably
10. stop tracking
    1. 
11. point to MOSS and take a series of images there
    1. 
    2. take_image_latiss

Summer meeting notes:

• Merlins thing basically works
• Juan Lin’s does much better ISR
• —> take their ISR, then do a peak finding and source fitting for both getting moments and centroiding using merlin’s method and gals
• Now, go through the data, do rotation so that we are in x and y, and seeing what we see (rotate the centroid coordinates after)
• preops notebook in GIT!!!!
• Improperly masked bad columns? - ISR mostly has worked
• Not perfect - going to have to check for outliers, etc.
• Running through the full 9000 images has to be done
• Elana knows relationship between rotation az/el and we will matrix and put in the sign

Notes 9.22

from this plot of data from two images, it seems like the sourcing pair that is split is the sources at x distance of ~0 

Looking at the plot, this is probably the bottom two sources (which makes sense, as the very bottom source is the one with the bad centroiding).

Now going to try finding why they split.

Why does it seem like we are still plotting the dataframe with data that does not necessarily have all four sources? Are we plotting over points here?

Split the plot into plotting by the source pair (0-5); it seems that

a) sources are not being paired consistently, so we have a few groups that are split 1/2 and 1/2 

b) the smaller two groups are actually from the same pair of beams, and the distance between them in y is changing dramatically

Now, we want to find which physical beams are in pair 3. From the dataframe it looks like pair 3 is composed of source_id_1 = 1 and source_id_2 = 2.

• Are we misidentifying one of the sources sometimes, or are we actually seeing that much motion in the same pair?

Which x and y coordinates do these source_id values correspond to?

Plotting our four groups of peaks gives me this, which does look like we are plotting the same shape as the images I have that look like the above. However, maybe it's the COM plotting that is being difficult; when I plot grouping by the positions relative to the COM in x and y (as the pairwise distances function does), I get weird chunks in my groupings that don't conform to the expected peak positions.

Why would the center of mass function be splitting up these groups? The code for the COM groups is:

'''

def calculate_com(group):
# Compute Center of Mass (COM)
com_x = group['centroid_x'].mean()
com_y = group['centroid_y'].mean()

# Add COM to the DataFrame
group['COM_x'] = com_x
group['COM_y'] = com_y

# Calculate position relative to COM
group['pos_rel_COM_x'] = group['centroid_x'] - com_x
group['pos_rel_COM_y'] = group['centroid_y'] - com_y

return group

'''

It is applied to the dataframe, and then new columns are added relating to COM. I think it must be the .mean() call from the calculate_com function, because the other major operation is just subtraction and should not throw relative spacing off (should just shift it).