Mon Sep 29 10:09:29 2025 INFO: Fill completed in 9min 25secs

Note TCs did not saturate at -200C today, weather is changing.

Note that plot is being produced by ndscope-test. The time axis label is no longer being cut.

TITLE: 09/29 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
OUTGOING OPERATOR: Ibrahim
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 6mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.42 μm/s 
QUICK SUMMARY:

• We've been locked for 7 hours
• 07:16 UTC Observing
• Secondary microseism is slightly elevated

Got called at 11:50 after PRMI locking failed for the second time. As I was prepping to move some mirrors to try and lock PRMI (initial alignment was done), PRMI locked and then DRMI.

IFO just needed some threat by opservation.

Watched guardian go into NLN as of 07:14 UTC and now OBSERVING.

Reset myself as OWL.

TITLE: 09/29 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Locked for 5 hours. The relock had an odd SRM M3 Wd trip during DRMI acquisition, but once untriped it went through Mich Bright, then PRMI, then it got DRMI. 
LOG:

• 2235 Lock loss
• 0005 Observing
• 0027 S250929c
•  

Looks like when one of the triggers for SRCL turned on, it tripped M3 a handful of seconds later. Another odd thing I'm seeing after I've untripped and tried PRMI is that the triggering seems to be turning on and off rapidly.

1443133532

Nothing obvious.

TITLE: 09/28 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
INCOMING OPERATOR: TJ
SHIFT SUMMARY: Quiet shift, we stayed locked the entire time.
LOG: N/A

The LSC front end has an FPU (floating point unit) error. The recent range drop post glitch looks to line up with a ~50 SNR low frequency glitch as seen on the Omicron plot on nuc27, and 2.5 hours ago there's some extra noise in the low frequency SQZ blrms. The recent glitch look to be from  =< 450Hz, as it's seen only in BAND_1-5.

• 13:16 UTC Observing

TITLE: 09/28 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 4mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.39 μm/s 
QUICK SUMMARY: Locked for almost 7 hours, calm environment.

Sun Sep 28 10:10:39 2025 INFO: Fill completed in 10min 35secs

TITLE: 09/28 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
OUTGOING OPERATOR: Ibrahim
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 7mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.35 μm/s 
QUICK SUMMARY:

• We've been locked for just over an hour
  • 13:!6 UTC Observing

Got called at 4:50 due to a mysterious SRM trip at 4:47 AM. IFO was in SRC ALIGN for initial alignment and SRM was railing during PREP_FOR_SRY. ST2 and ST3 sus tripped, which makes me think that initial alignment may have caused it? Microseism is on the rise but nothing jumps at me otherwise (attached).

Either way, I untripped it and waited until IFO got to DRMI which it just did. Flashes look good. Will continue light monitoring but I think guardia can take it from here.

Reset myself as the OWL.

TITLE: 09/28 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Quiet shift, locked for 5 hours. Range is much more stable than the last lock and up a few Mpc.
LOG:

• 2353 Observing

TITLE: 09/28 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 4mph Gusts, 1mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.33 μm/s 
QUICK SUMMARY: Just got back to observing after a 31 hour lock. 

Relocking took a bit longer due to an earthquake off of the coast of oregon rolling through. The only thing of note was that I changed the threshold in ALIGN_IFO for the MICH Bright convergence checker from 1.5 to 2. This average convergence checker I've seen take longer then it should so I wanted to try to speed it up a bit.

TITLE: 09/27 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: TJ
SHIFT SUMMARY: The SQZer struggled a little before and during the calibration measurement, 1 lockloss that we are still recovering from (move spots as of 23:30).
LOG:                                                                                                                       

• 15:25 UTC Superevent S250927ck
• 17:31 UTC Superevent S250927cy
• 18:22 UTC Dropped Observing from the SQZ LO losing lock and struggled to relock alog87175
• 19:23 UTC  CAL measurement
  • 19:33 UTC More SQZ issues
• 19:53 UTC Observing
• 21:34 UTC lockloss
• 22:16 - 22:28 UTC earthquake mode, 5.2 from Oregon cascadian subduction zone. (We didn't see it on seismon or usgs until after it hit)
• 22:39 UTC Initial alignment

FAMIS26688

The EX fan2 is starting to get noisy. EY fan 1 is also starting to see some extra noise during the night (see the green trace on attachment 2).

Corner station and other outbuildings look good.

Here is a summary of some results from the open loop gain measurements of DHARD Y and CHARD Y, and the implementation of a new CHARD P low pass:

DHARD Y

I measured the DHARD Y open loop gain, results shown here. The dark blue trace shows the original measurement, showing 17 degrees of phase margin and gain peaking of 10 dB. Looking at the loop design, there are three different boost filters applied to DHARD Y, compared here. These boosts in combination seem to be destroying all the phase of the loop. I took a measurement with the 0.9 Hz boost disengaged (FM3), which is shown in the green trace. Then, I disengaged the 0.5 Hz boost (FM4) and remeasured, shown in the red trace. This improved the phase margin to 32 degrees. This obviously resulted in less microseismic suppression. I adjusted the 0.5 Hz boost (FM4) and decided we should operate without the boost in FM3. This plot compares the original loop error signal and RMS with all three boosts (gold), the error signal and RMS without FM3 and FM4 boosts (green) and then error signal and RMS with the updated FM4 boost (red). The RMS increased 50% without both boosts on, the improved boost returns the RMS to that value. There is now more phase margin in the loop. Updated in guardian and ASC high gain script, SDFed (1,2).

CHARD Y

I measured the CHARD Y open loop gain, results shown here. The file had an old reference trace from 2023, shown in bluegreen in the reference. The gray trace shows the first measurement I made today of CHARD Y. The gain appeared to be way too low. I raised the gain to match the old reference, which was a gain increase of 6 dB. Here is a comparison of the RMS of CHARD Y from 14 hours ago (bluegreen reference) and now (red live). The microseism level is the same between these two measurements. Overall, this reduces the RMS of the loop, so I think this is a good adjustment. This is updated in the guardian and ASC high gain script, also SDFed.

CHARD P

I implemented a new CHARD P low pass filter to reduce CHARD P coupling that is apparent in coherence measurements (example).

Here is a comparison of the old controller (red) with the new controller (blue). This replaces the lowpass filter in FM8 with the filter in FM9. I also disengaged the old 200 Hz lowpass that was previously in FM10, as it wasn't doing much. SDFs (1,2). Guardian code and ASC high gain script updated.

The coherence of DARM with CHARD P has reduced, as expected, and increased for CHARD Y, also as expected. I have since created a new lowpass for CHARD Y that should reduce the coherence and is ready for testing at the next opportunity (comparison).