Violin mode ETMY mode 1 was turned off via the VIOLIN_DAMPING gaurdian around 05UTC last night, log excerpt below. Leaving it with no gain had it not increasing and actually decreasing but at a rate that was basically stagnant. Currently, FM1&10 with a gain of -0.1 seems to be working, but I know that this gain has had the damping turn around later so I might damp it till it gets to a low enough level then turn it off.

2025-01-18_05:44:47.588350Z VIOLIN_DAMPING [DAMP_VIOLINS_FULL_POWER.run] timer['shortSleep'] done
2025-01-18_05:44:47.647819Z VIOLIN_DAMPING [DAMP_VIOLINS_FULL_POWER.run] ETMY mode 1 is growing!!  turning off gain
2025-01-18_05:44:47.648013Z VIOLIN_DAMPING [DAMP_VIOLINS_FULL_POWER.run] inUse_mon {'starting_mon': 3.4628171681603113, 'starting_gai
n': 0.1, 'done_damping': False, 'inUse_mon': 3.4628171681603113, 'reset_number': 0, 'guardian_gain': 0.1, 'guardian_damping': True}
2025-01-18_05:44:47.648113Z VIOLIN_DAMPING [DAMP_VIOLINS_FULL_POWER.run] current monitor level 4.462891708360431
2025-01-18_05:44:47.648788Z VIOLIN_DAMPING [DAMP_VIOLINS_FULL_POWER.run] ezca: H1:SUS-ETMY_L2_DAMP_MODE1_GAIN => 0

TITLE: 01/18 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 159Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 6mph Gusts, 4mph 3min avg
    Primary useism: 0.06 μm/s
    Secondary useism: 0.19 μm/s
QUICK SUMMARY: Locked for 25.5 hours. No alarms, but ETMY violin mode 1 seems to be slowly ringing up. I'll start work on damping that. The primary useism seems to have gone up a bit in the last 6 hours, but not the secondary.

TITLE: 01/18 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY: Observing at 157 Mpc and have been Locked for almost 16 hours. Quiet night. I did find the Paging System power cord plugged in - not sure how long it's been plugged in but I unplugged it.

We had a candidate come in earlier (S250118t), and then one just came in a couple of minutes ago (S250118az)!

Our range hasn't been great this evening. I'm not sure why we've been fluctuating so much, but I don't think it's related to squeezing, and the low range diaggui didn't show much. Right now we're back to doing okay range-wise.
 

LOG:

02:32 Superevent candidate S250118t

05:58 Superevent candidate S250118az

Currently Observing at 153 Mpc and have been Locked for 14 hours. Our range has been slowly dropping over the part few hours. Not sure why yet

TITLE: 01/18 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 160Mpc
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 10mph Gusts, 7mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.23 μm/s
QUICK SUMMARY:

Observing and have been Locked for over 10 hours. Range dipped a bit earlier due to unknown reasons, but looks to be slowly coming back up.

Closes FAMIS#26354, last checked 82116

** Looking at last 2 weeks since last checked was on 01/04

Corner Station Fans (attachment1)
- All fans are looking normal and within range. There did look to be a period of extra noise following some sort of work done yesterday (Thursday 01/16) on MR FAN1 2, but that looks to have calmed down now.

Outbuilding Fans (attachment2)
- All fans are looking normal and are within range.

E. Goetz, J. Kissel, L. Dartez

Summary:
There is evidence that some of the lines found in the gravitational wave band are actually aliased lines from higher frequencies. So far it is unclear exactly how many of the lines in the run-averaged list are due to this problem and if the lines are stationary or if violin ring-ups may induce more lines in band due to aliasing artifacts. Further investigation is needed, but this investigation suggests that the current level of anti-aliasing is insufficient to suppress the artifacts at high frequency aliasing into the gravitational wave band.

Details:
We used the live, test-point acquisition of the 524 kHz sampled DCPD data in DTT, channel H1:OMC-DCPD_B1_OUT (equivalent to the nominal H1:OMC-DCPD_B0_OUT channel used in loop). This channel had the same 524k-65k and 65k-16k decimation digital AA filtering applied. The time series was exported from DTT and processed by stitching together the time segments into a single time series. Then one can process the time series using the scipy.signal.welch() function of 1) the full 524 kHz sampled data, 2) 524 kHz sampled data decimated (no additional AA filtering) by a factor of 32 to get the 16 kHz sampled frequency data, 3) 524 kHz sampled data decimated using additional AA filtering by using the scipy.signal.decimate() function which has a built-in anti-aliasing filter.

We also plotted in DTT the individual channels against the 16k H1:OMC-DCPD_B_OUT_DQ channel, showing that some of the lines are visible in the in-loop DCPD 16 kHz channel, but not visible in the test point 524 kHz channels.

Figure 1: ASD of raw 524 kHz data (blue), decimated data without any extra anti-aliasing filter applied (orange), and decimated data with additional anti-aliasing filtering (green). Orange peaks are visible above the blue and green traces above ~750 Hz.
Figure 2: ASD ratio of the decimated data without anti-aliasing filtering to the raw data showing the noise artifacts
Figure 3: Zoom of figure 2 near 758 Hz
Figure 4: ASD computed from DTT showing DCPD B Ch 1, 5, 9, 13 and and the H1:OMC-DCPD_B_OUT_DQ channel at the same time as the 9 and 13 channels were acquired (limitations of the front end handling of 524 kHz test points to DTT)
Figure 5: Zoom of figure 4 near 758 Hz

We were also interested in the time-variability of these artifacts and watched the behaviour of H1:OMC-DCPD_B_OUT_DQ, and saw amplitude variations on the order of factors of a few and frequency shifts on the order of 0.1 Hz, at least for the artifacts observed near 758 Hz.

Figures 4 and 5 indicate that there are more artifacts not necessarily directly caused by aliasing; perhaps these are non-linearity artifacts? This needs further study.

A count of the number of 0.125 Hz frequency bins from 0 to 8192 Hz of the ratio between downsampling without additional anti-aliasing filtering and the raw 524 kHz ASD indicates that ~4900 bins are above a threshold of 1.1 (though most of those bins are above 2 kHz, as indicated by figure 2).

Fri Jan 17 10:09:34 2025 INFO: Fill completed in 9min 30secs

Laser Status:
    NPRO output power is 1.842W
    AMP1 output power is 70.11W
    AMP2 output power is 137.6W
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN
    PDWD watchdog is GREEN

PMC:
    It has been locked 30 days, 21 hr 54 minutes
    Reflected power = 25.75W
    Transmitted power = 102.5W
    PowerSum = 128.2W

FSS:
    It has been locked for 0 days 2 hr and 54 min
    TPD[V] = 0.773V

ISS:
    The diffracted power is around 4.0%
    Last saturation event was 0 days 2 hours and 54 minutes ago

Possible Issues:
    PMC reflected power is high

TITLE: 01/17 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 5mph Gusts, 3mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.22 μm/s
QUICK SUMMARY:

H1 had 2-locklosses overnight which came back automatically.  Ther was a drop from 0944--0945 due to PI24.  Microseism is squarely between 50th-95th percentile and winds are low.  Nuc31's USGS website needed a refresh; nuc35's MC2 & PR2 cameras are offline/blue.

TITLE: 01/17 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:

IFO is in NLN and OBSERVING as of 22:34 UTC (7hr 30 min lock)

Smooth shift locked the whole time.
LOG:                                                                                                                                                                                                                                

TITLE: 01/17 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
OUTGOING OPERATOR: Tony
SHIFT SUMMARY:

IFO is in NLN and OBSERVING as of 22:34 UTC

LOG:

None

The increase in space temperature in zones 2A and 5 in the LVEA this morning appears to be from sun exposure on the building. Both zones experienced rapid increases at the same time, at the same rate of increase. Both zones have the most sun exposure during the morning hours. The space sensors are located in the exterior walls which makes them susceptible to radiant heating during periods of direct sun exposure. These sensor locations also caused issues at the mid and end stations, when the southern exposures routinely read colder when the winds blow. 

I have made slight adjustments to the set points in zones 2A and 5 to accommodate for the sun exposure. If it continues to be a problem, sensor relocation will likely be needed.   

We haven't aligned the OMC ASC for while so today I did Gabriele's method where we inject lines in the four OMC ASC loops at different frequencies and then demodulate the 410 Hz PCAL line at these frequencies and then at 410Hz to look at which combination of offsets improves our optical gain the most.

The plot of BLRMS of the DCPD_SUM_OUT at 410 Hz vs. QPD offset is shown below.

The start and end times used were 17:22:40 UTC and 17:42:40 UTC.

The detector was in NLN s but squeezing was turned off.

The code is at /ligo/home/jennifer.wright/git/2025/OMC_Alignment/OMC_Alignment_2025_01_16.ipynb.

Usually the start and end times the plots use contain some times without the OMC ASC lines but that was not possivle here as we went to NLN_CAL_MEAS before I had turned off the lines.

Looking at the plot, I think we need to change

H1:ASC-OMC_A_PIT_OFFSET by -0.1

H1:ASC-OMC_A_YAW_OFFSET by 0.075

H1:ASC-OMC_A_PIT_OFFSET by -0.075

H1:ASC-OMC_A_YAW_OFFSET by 0.08

or something close to these.

As a follow up to my other post about ETMX glitches, I looked at using a strategy used in DRMI locking to try to help the IFO ride through the high frequency glitches that have been causing locklosses. On the BS suspension the ISC path includes filters that whiten the high frequency ISC signal, a limit is applied to that whitened signal then it's dewhitened. Think the filters used for this are a zpk(1,200,1) and it's inverse, with a limit of 50000 in the ISC input to the BS.

I attempted to look at the impact of doing that on a couple glitches leading up to a lockloss. I got data for the ESD drive from one of the lock losses and used lsim in matlab to model the change in the ESD timeseries. The attached image shows the timeseries for each step of whitening, limit and dewhiten compared to the original glitch. It's not a proper model of the DARM loop, Sheila and I might talk about doing that, I just wanted to see if doing the simplest estimate would blow up before digging deeper into it. 

Thick blue is the original ESD drive from one of the quadrants, Red is the whitened siganl, yellow is the whitened signal limited to below the saturation level for the ESD, and the thin purple line is the dewhitened, final timeseries. The thin line doesn't show crazy behavior and stays below the saturation threshold (2^19*275, which comes from some adjustments made to accomodate the new dac on ETMX). 

I expect if this worked, it would inject some higher frequency junk into this segment, but the glitches already do that. The hope is this would reduce the drive from these high frequency saturations and let the IFO ride them out.

J. Kissel

More changes along the lines of LHO:82261. As we continue to explore the configurations of the OMC DCPD channels, probing anti-aliasing and ADC noise, we find it helpful to have all of the frequency-dependent, actual physical channel filter differences available in all four test banks. As such, I've
- changed the name of gain(0.25) filter from "sum2avg" to "sum4avg." Pun intended.
- Copied the DCPD A "NewV2A" and "NewAW" from A0 now called "A_V2A" and "A_AW" into FM2 and FM3, 
- Copied the DCPD B "NewV2A" and "NewAW" from B0 now called "B_V2A" and "B_AW" into FM4 and FM5, and
- Moved all of the channel-independent gains to the bottom row, 
    FM6: "18b_cts2V" gain of 40 / 2^18 [V/ct]
    FM7: "sum4avg" gain of 0.25
    FM8: "A2mA"
- keeping only the FM1, 1 Hz 5th order elliptic highpass and the digital AA decimation filters, Dec65K and Dec16K in FM9 and FM10 in place.

This filter file change has been loaded (because we're not in observing at the moment), and committed to the userapps repo,
     /opt/rtcds/userapps/release/cds/h1/filterfiles/
         H1IOPOMC0.txt                                rev 30421.

TITLE: 01/16 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 6mph Gusts, 3mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.23 μm/s
QUICK SUMMARY:

Comissioning Activities: 
Calibration sweep: completed
OMC ASC Alignment test : Completed
PR2 Beam spot measurement : Ongoing.
PEM CPS Slider Ghost beam investigations: ongoing
SRC Injection sweeps: Complete
Squeeze measurements: Ongoing.

Lockloss from NLN_CAL_MEAS @ 18:56 UTC
 

Alarm Handler:
Dust PSL  101 again.

Repeated 82151, with H1:IOP-OAF_L0_MADC{2,3}_TP_CH{10-13} 65kHz channels on CO2Y. WP# 12261.

Plots attached of the DC and AC out channels. These signals are straight from the PD in counts, before the filtering to undo the D1201111 pre-amp listed in 81868. PWM is at 5kHz, as can be seen in the spectrum.

(Niko, Corey, Hugh, Keita, Georgia, Craig, Richard, Fil, Ed)

Today was the big day to squeeze in a variety of HAM1 Tasks.  Once the doors were removed this morning, a suite of activities ensued:

• HAM1 Checklist items post doors removal:   
• Installed (2) separate cable runs for the (4) L4C pods to be installed.
• Installed (2) cables for the new in-vac REFL_B PD.
  • Continuity test run on cables:  PASSED
• New REFL PD assembled & coarsley installed
  • Flashlight test (& compared to original REFL_A PD):  PASSED
• 90/10 beamsplitter removed from Beam Diverter & swapped with a High Reflector + Black Glass
  • Beam Diverter operation tested:  PASSED
• (2) L4C Pod Cable runs were tested with emulator:  PASSED
• Installed (4) L4C Pods inside the HAM1 Optic Table
  • Adjusted ASC_REFL_A Beam-dump to clear optics table 1/4-20 hole.
  • Removed cable clamp near RM1 (for the REFL_A PD) to allow for access work for installation.

Hugh will post specifics for L4C installation and for remaining tasks (and I will post photos).

Keita will post specifics for REFL_B PD installation.