At 00:42:03 UTC  Verbals announced an incoming 5.5M Earthquake from Tonga.
At 00:56:16:UTC H1 dropped from Observing due to a SQZr Unlock that was very likely caused by the increased ground motion.
We went back to Observing at 01:01:39 UTC after the SQZ Man relocked itself.
I did put the OPS mode into earthquake for that moment.
At 01:02:10 UTC Earthquake mode was activated.

TITLE: 08/22 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 16mph Gusts, 9mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.19 μm/s
QUICK SUMMARY:

I inherited a 15+ hour lock from the day shift operator.
Everything looks like its running well.
Wind forcast looks great as well.

 

TITLE: 08/22 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
INCOMING OPERATOR: Tony
SHIFT SUMMARY: Observing at 155Mpc and have been Locked for over 15 hours. Nothing happened during my shift at all.
LOG:

14:30 UTC Observing and have been Locked for 6.5 hours
                                                                                                                                                                        

Leo, Camilla, Jennie W.

Over the summer, a robust mode-matching simulation for the SQZ beam to the OMC was built using the a la mode library. This report serves to summarize the current state of the simulation and the relevant information one can extract from it.
Link to git code: https://git.ligo.org/leendert.schrader/alm-beam-simulation-for-sqz/-/tree/main SQZ_simulation_v4.m is currently the most recent version. 


#1 A detailed description of the squeezed beam path. 
Distances, curvature radii, incidence angles, refractive indices, etc. are all within the code file with comments on where they were obtained. This includes all information necessary to propagate the beam starting at the SQZ output (BM4), through ZM4-6, the OFI, SRM, and into the OMC.
These can also be found in the google doc in T2500228, though the curvature radii for ZM4/5 are not what are used in the simulation. 

Related aLogs: 85282, 85339 


#2 The beam characteristics between ZM5 and ZM6.
Using the beam profiling data from SQZT7 one can plot a "q manifold" which assigns a q parameter with respect to strain gauge values for ZM4 and ZM5.
That is, if one knows the strain gauge for ZM4/5, they can know the beam after ZM5.
Attached is a sample of the q manifold obtained by fitting the horizontal beam width data. 

Related aLogs: 85917, 86365, 86519, 85775 


#3 Simulated and experimental mode-matching at the OMC. 
Simulated: By Propagating the q manifold forward to the OMC using the beam path constructed in a la mode, we can simulate mode-matching with respect to ZM4/5 strain gauge values. The simulation was found to be accurate for high mode-matching, but underestimates matching on the fringes of the strain gauge ranges (compared to collected data). 
Experimental: Multiple OMC scans for mode-match were obtained, which allows us to characterize mode-matching across any strain gauge values for ZM4/5. 

Attached is a picture of both the simulated and experimental matches against each other. The surface with a grid fits the experimental data, while the surface without grid is the simulated data. 

Related aLogs: 86445, 86467, 86520


#4 ZM4 and ZM5 curvature estimates.
We estimate ZM4 curvature by interpolating data in E2100289. Note that preload was increased from 46 in lb to 75 in lb, hence why we had to "interpolate."
We predict the curvature of ZM4 acts as 
     R_ZM4 = 2/(-0.026296*V_ZM4 - 0.310465) 
where V_ZM4 is the strain gauge value for ZM4.
This equation is achieved by assuming a linear voltage - to - optical power relationship (hence the '2 divided by a linear term'). The q manifold is then used to predict the ZM5 curvature values.
Therefore, by ranging the strain gauge in the simulation GUI, one can find simulated ranges for ZM4 and ZM5 curvature. 
Note: ZM4 was selected for the above estimate, as we found it behaved "more linearly" than ZM5.


Miscellaneous: the simulation contains the unique SRM ray transfer matrix in the M_SRM variable (see the first interim progress report in T2500228 for details on computation). 


For all reports and presentations related to the summer project, see the main DCC document T2500228.

We have now been Locked for almost 13 hours and have been in Observing since I got in this morning. Nothing to report.

Fri Aug 22 10:08:42 2025 INFO: Fill completed in 8min 38secs

Closes FAMIS#26550, last checked 86343

Laser Status:
    NPRO output power is 1.865W
    AMP1 output power is 69.91W
    AMP2 output power is 140.3W
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN
    PDWD watchdog is GREEN

PMC:
    It has been locked 9 days, 22 hr 41 minutes
    Reflected power = 23.7W
    Transmitted power = 105.3W
    PowerSum = 129.0W

FSS:
    It has been locked for 0 days 7 hr and 57 min
    TPD[V] = 0.8324V

ISS:
    The diffracted power is around 4.0%
    Last saturation event was 0 days 12 hours and 31 minutes ago

Possible Issues:
    PMC reflected power is high

TITLE: 08/22 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 15mph Gusts, 10mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.19 μm/s
QUICK SUMMARY:

Observing at 153Mpc and have been Locked for 6.5 hours.

TITLE: 08/22 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
INCOMING OPERATOR: TJ
SHIFT SUMMARY:

Uneventful shift up until a M7.5 EQ took over!  Shift's almost over and I'm guessing we have another 45+min until we get out of LARGE_EQ mode.  Will be switching over to automatic operations shortly and gave TJ a status text earlier tonight.  Picket Fence continues to flash yellow.
LOG:

• Tony noticed the Teamspeak server was down at the beginning of the shift and all other servers were down except virgo's--so we switched to using the virgo Teamspeak for the night.
• 00:09-00:15 shuttering shutters in the PCal Lab (tony)
• 01:04:58 - 01:05:00 Big glitch on H1 (but nothing out of the ordinary seen on other FOMs)
• 02:36 LOCKLOSS due to Big EQ

H1's been down about 45min so far due to a M7.5 EQ....waiting for the earth to calm down, but the R-Waves are barely rolling through now.

Jeff, Oli

Today we tested out the SR3 estimators for both Pitch and Yaw (86491). The ASC loops where we see a difference are DHARD, MICH, SRC1, and SRC2, since these all go through the SRC to their output ports. As expected, we don't see any effect on CHARD, PRC, or INP.

I've plotted comparisons of the ASC control and error signals during those times along with a reference time of earlier that morning.

The ultimate conclusion is that the SR3 P and Y estimators do work to make some of the ASC noise better, and the good thing is that in the places where we see that the estimator makes the noise worse, they all seem like easy improvements/fixes! The amount of improvement that we see doesn't look like much, but that's also expected since it's just SR3 that has the estimator out of the several suspensions in each ASC path. We expect that as we add more estimators along these paths, we will keep picking away at the suspension noise. We already see really impressive broadband improvement between 1-5 Hz on SRC1 and SRC2!

Main areas of concern:
    - For all ASC loops and both P and Y, we see heightened SR3 resonances on around 0.7 Hz when the SR3 P estimator is on. This is because the OSEM P blend filter was made without including the 0.7-0.8 Hz mode. That is being added in and that should solve that issue
    - Between 0.1 and 0.2 Hz for some loops, turning on the estimators puts in some extra noise from the GS13s, which aren't as sensitive at those lower frequencies. To solve this, we will be adding a high pass filter above those frequencies
    - A few peaks aren't being damped as well with the estimator as they were with normal damping; however, now that we've shown that the estimator decreases our noise(86455, 86503), we are hoping to be able to increase gain somewhere in the estimator system (possibly in SR3_M1_EST_Y_FUSION_MEAS_BP) to better damp our resonances while still seeing improvements in noise as compared to normal damping

Here are the times used to grab the traces:
Estimator ON for SR3 P and Y (RED) 2025-08-21 16:35:00 UTC
Estimator ON for SR3 Y (BLUE) 2025-08-21 15:34:06 UTC
Estimator ON for SR3 P (GREEN) 2025-08-21 16:05:00 UTC
Estimator OFF (PINK) 2025-08-21 10:27:00 UTC

I created an updated blend for the SR3 pitch estimator. These are in the SUS SVN next to the first version. (see LHO log 84452)

The design script is blend_SR3_pitchv2.m

the Foton update script is make_SR3_Pitch_blend_v2.m

these are both in {SUS_SVN}/HLTS/Common/FilterDesign/Estimator/  - revision 12608

The update script will install the new blends into FM2 of SR3_M1_EST_P_FUSION_{MEAS/MODL}_BP with the name pit_v2. pit_v1 should still be in FM1. Turn on FM2, turn FM1 off. 

Jeff and Oli tried the first one, and see that the first 2 modes (about 0.65 and 0.75 Hz) are seeing more motion with the estimator damping than the normal damping. To correct this, _v2 add OSEM signal to the estimator for those modes. See plots below - First 2 are the _v2 blend and a zoom of the _v2 blend. figure 3 shows the measured pitch plant vs. OSEM path - the modes line up pretty well. There is a bit of shift because the peaks are close together. I expect hope this will not matter. Figure 4 shows the plant vs. the model path. Now all 4 modes are driven by the measured OSEM signal instead of the model. 

It is interesting to see that the model was not doing a good job of predicting the motion at the first 2 peaks. This is (I guess) because either (a) the model and the plant are different - or - (b) there are unmodeled drives pushing the plant (the suspension) that the model doesn't know about. 

I'm guessing the answer is (b - unmodeled drives) and is likely from DAC noise. I think this because
1 - The plant fit is smooth and really good.
2 - In the yaw analysis that Edgard and Ivey are doing (not yet posted) the first mode of the yaw plant can be seen with the OSEM, but the ISI motion is much too small to excite that level of motion. But the OSEM can see motion, so something is exciting that motion.
3 - The DAC noise is the only thing I can think of.

Quick chat with Jeff indicates that the DAC noise models at those frequencies are not well trusted. We'll try something anyway and see if it is close. I don't see how to use the estimator to deal with that noise - we'd need to have an accurate realtime measurement. 

At the beginning of this shift, Tony noticed that we had errors for the LHO Control Room Teamspeak.  He mentioned this to Jonathan, and they found out that all the LIGO/MIT Teamspeak servers are down and that we should use the Virgo server to maintain communications.  So---You can find the "LHO Control Room" teamspeak account at:

• server:  teamspeak.ego-gw.it
• room:  EM Follow-up

Of course you can always phone the Control Room as well.

TITLE: 08/21 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: SEISMON_ALERT
    Wind: 12mph Gusts, 6mph 3min avg
    Primary useism: 0.05 μm/s
    Secondary useism: 0.17 μm/s
QUICK SUMMARY:

H1's been locked 3.25+hrs.  TJ passed on what he needed to do for relocking earlier (I've not had to lock H1 for any of my last 6-evening shifts in a row this week...we'll see how tonight goes for my last (7th EVE) shift of the week!).  Environmentally, we had a small EQ from Japan roll through, winds are low, and µseism has slowly popped above the 50th percentile in the last 24hrs.

Leo, Jennie, Camilla

Followed setup instructions from 80010, with 75mW injected in the SEED beam, we had 1mW on OPO_IR_PD_DC slightly lower than last time. Also took SQZ_FC to FC_MISALIGNED.  And opened SQZ beam divertor and fast shutter. Have counts of ~60 on ASC-AS_A and B and 7e-4 on ASC-OMC-A and B NSUMs. Jennie took the OMC PZT down to zero to start and then ran a template userapps/../omc/h1/templates/OMC_scan_sqz_beam.xml.

Repeated mode scans with different ZM PSAMs offsets, the DC centering loops could account for the pitch change for PSAMs, for the extreme PSAMS values, I increased the servo limiter from 85 to 95. 

• nominal: ZM4 6.0V strain, ZM5 -0.4V strain. 
• ZM4 9.5V strain, ZM5 -0.6V strain. 
• ZM4 6.0V strain, ZM5 -4.5V strain. Note that the OMC Pitch QPDs were off around -0.1
• ZM4 6.0V strain, ZM5 -5.3V strain. Note that the OMC Pitch QPDs were off around -0.1
• ZM4 9.0V strain, ZM5 2.0V strain
• ZM4 3.0V strain, ZM5 2.0V strain
• ZM4 8.0V strain, ZM5 -2.0V strain. Note that the OMC Pitch QPDs were off around -0.1
• ZM4 4.0V strain, ZM5 -2.0V strain. 
• ZM4 9.5V strain, ZM5 -5.0V strain. Realized OMC ASC had been off before this measurement (we had turned it on but them changed OMC GRD which turned it off again)
• Repeat of ZM4 9.5V strain, ZM5 -0.6V strain with OMC ASC on.

Jennie and Leo have the data to analyze. 

Leo, Jennie, Camilla, WP 12694

Jennie followed instructions for set up in 85775. We removed the SQZ beam iris at the bottom of the LPM (added for alignment capture during OFI vent work). Then took beam profiles in this SQZ path of the SEED beam with various PSAMS settings, adjusted PSAMS settings as in 85775 and used the servo for nominal settings. All data is attached. Jennie then reverted settings back to nominal.