Followed the usual wiki instructions.

Simulines command run:

gpstime;python /ligo/groups/cal/src/simulines/simulines/simuLines.py -i /ligo/groups/cal/H1/simulines_settings/newDARM_20231221/settings_h1_20250212.ini;gpstime

Simulines start:

PDT: 2025-03-27 08:35:50.875109 PDT
UTC: 2025-03-27 15:35:50.875109 UTC
GPS: 1427124968.875109

Simulines stopped prematurely due to some SCRL offsets getting changed midway through:

PDT: 2025-03-27 08:54:32.154549 PDT
UTC: 2025-03-27 15:54:32.154549 UTC
GPS: 1427126090.154549

Simulines started again:

PDT: 2025-03-27 09:01:37.213384 PDT
UTC: 2025-03-27 16:01:37.213384 UTC
GPS: 1427126515.213384

Simulines end:
PDT: 2025-03-27 09:25:15.138110 PDT
UTC: 2025-03-27 16:25:15.138110 UTC
GPS: 1427127933.138110

Files:

2025-03-27 16:25:14,982 | INFO | File written out to: /ligo/groups/cal/H1/measurements/DARMOLG_SS/DARMOLG_SS_20250327T
160138Z.hdf5
2025-03-27 16:25:14,990 | INFO | File written out to: /ligo/groups/cal/H1/measurements/PCALY2DARM_SS/PCALY2DARM_SS_202
50327T160138Z.hdf5
2025-03-27 16:25:14,995 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L1_SS/SUSETMX_L1_SS_202
50327T160138Z.hdf5
2025-03-27 16:25:15,000 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L2_SS/SUSETMX_L2_SS_202
50327T160138Z.hdf5
2025-03-27 16:25:15,004 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L3_SS/SUSETMX_L3_SS_202
50327T160138Z.hdf5

Tony created the PCAL{X,Y}_STAT nodes a few weeks ago, and has been monitoring and testing over that time. They look to be working as intended, flagging any major issues with the PCAL system. I've now removed them from the excluded nodes list that the IFO node looks at so that now if either of these nodes is out of its nominal state or the node is not OK==True, then the IFO node will not be OK and we will not be able to go to Observing.

J. Kissel, S. Dwyer, T. Shaffer

TJ was diligently running at regularly scheduled calibration measurement suite with the current nominal configuration of the IFO. Sheila and I got too excited about what other measurements we needed to do during the commissioning period today, and I quickly and boldly made the assessment that the simulines sweeps were done by just looking at the front wall DARM FOM. And said "we can go ahead with the first [commissioning] measurements" and changed the SRCL offset to grab an augmented IFO configuration sweep as planned. We realized only ~2 mins after that the nominal configuration sweep *was* still going, and this is me eating my hat. Sorry team.

TJ killed the simulines session, which apparently automatically cleans up the calibration sweep measurement report infrastructure, so there's no evidence of it.
So, today's regular calibration has been spoiled.

The broadband injection in the nominal configuration did go forward to completion, that's
    /ligo/groups/cal/H1/measurements/PCALY2DARM_BB/
        PCALY2DARM_BB_20250327T153021Z.xml
The "nominal" configuration -- compared to what we want to change today:
    Filter Cavity Detuning = -34 Hz offset
    SRCL Offset -191 [ct]

Here's the measurements with the augmented IFO configuration, with 
    Filter Cavity Detuning = -28 Hz offset
    SRCL Offset -306 [ct]

    /ligo/groups/cal/H1/measurements/PCALY2DARM_BB
        PCALY2DARM_BB_20250327T155611Z.xml
    /ligo/groups/cal/H1/measurements$ ls */*20250327*.hdf5
        DARMOLG_SS/DARMOLG_SS_20250327T160138Z.hdf5
        PCALY2DARM_SS/PCALY2DARM_SS_20250327T160138Z.hdf5
        SUSETMX_L1_SS/SUSETMX_L1_SS_20250327T160138Z.hdf5
        SUSETMX_L2_SS/SUSETMX_L2_SS_20250327T160138Z.hdf5
        SUSETMX_L3_SS/SUSETMX_L3_SS_20250327T160138Z.hdf5
Due to the augmented SRCL offset, these measurements should *not* be included in the collection of measurements used for creating estimates of residual sensing function systematic error.
The filter cavity detuning change only impacts the noise performance of the IFO, so if need be, you *can* still use the actuation function portion of the measurement suite.

TITLE: 03/27 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: 18mph Gusts, 10mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.34 μm/s
QUICK SUMMARY: Locked for 3 hours. DIAG_MAIN is reporting "RefCav transmission low", tagging PSL. No other alarms or notifications. Planned calibration and commissioning time today from 1530-1900 UTC.

TITLE: 03/27 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Observing at 156Mpc and have been locked for almost 1 hour. One lockloss during my shift but relocking went well and was almost completely hands off besides me selecting an initial alignment.
LOG:

23:30UTC Observing at 156 Mpc and locked for almost 12 hours
    01:55 Kicked out of Observing due to squeezer losing lock
    01:59 Back into Observing after squeezer got back to FDS

02:41 Lockloss
    - I immediately decided to start an initial alignment since the lock had been relatively long
04:13 NOMINAL_LOW_NOISE
04:15 Observing                                                                                                                                                                                                                                                                                                                 

Lockloss @ 03/27 02:41UTC after just over 15 hours locked

TITLE: 03/27 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 6mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.21 μm/s
QUICK SUMMARY:

Currently Observing and have been locked for over 13 hours. I forgot to put this in earlier when TJ was leaving oops

TITLE: 03/26 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY: Commissioning time for three hours this morning, which we stayed locked for. We have been locked for 11.5 hours now. I've been impatient and have tried damping down ITMY violin modes 5&6 by making small gain changes. I think I slightly sped it up, but barely.
LOG:

• 1521-1526 SQZr unlocked, relocked
• 1550 dropped Observing for ~20sec due to an accidental click in the control room
• 1600 Commissioning time start
• 1903 Back to Observing

Yesterday we were sitting waiting for the violin modes to damp before changing the OMC whitening, so I took advantage of the time to do some scans of the RF3 demod phase (which is labeled RF6 in beckhoff) with different SRCL offsets since we suspected that the SQZ angle servo might not work well during thermalization because of the changin SRC detuning. However, it seems that doesn't have much impact on the SQZ angle readback, and this servo should work fine with changes in SRC detuning.

The first subplot shows the ADF ellipse, and then the channels after the normalization that is used to turn it into a circle, these look the same for the two offsets.  The next plot shows the readback of the SQZ angle, which is arctan2 of the normalized signals from the first plot.  This relation ship is not linear, it should be described by the relationship Daniel wrote here: 49026

The bottom plot shows the sqz blrms, we want to operate the sevo where this is minimzed, where it seems that the sqz angle readback is a good error signal to use.

Wed Mar 26 10:13:03 2025 INFO: Fill completed in 12min 59secs

Gerardo confirmed a good fill curbside.

Reduced HAM7 rejected pump power and increased SHG launch, turned OPO trans setpoint up to 120uW and measured NLG with 76542 to be 58 (this was a little lower than with 120uW in 83370).

Data attached with filename shown on screenshot.

Note that I left the OPO servo gain at -8, but we have previously used -12dB for 120uW OPO trans (83370)

The squeezer unlocked, then relocked from 1521-1526UTC. The SQZ_OPO_LR node now has the message "pump fiber rej power in ham7 high, nominal 35e-3, align fiber pol on sqzt0".
 

J. Kissel, O. Patane, B. Lantz

After seeing my post of the current (2025-03-19) performance of the H1ISIBS in LHO:83470, Brian -- in his LHO:83473 comment -- rightly cautioned Oli to beware the difference between 
    (1) a "statistical" or "incoherent" model of the CART2EUL projection to the suspension point, where 
        . one takes the ASDs of the CART DOFs (which are inherently only containing amplitude information, no phase relation between channels), 
        . multiplies them by the CART2EUL coefficients, and 
        . takes the quadrature sum 
      to form an ASD model of the euler basis motion,
   vs.
    (2) a "linear combination" or "coherent" model of the CART2EUL project to the suspension point, where 
        . the time-series of each CART DOF are multiplied by the CART2EUL coefficients, 
        . the time-series are then coherently summed (where "coherently" summed just means the amplitude AND phase relationship between the channels has been preserved), and 
        . then an ASD is taken of that 
      to form an ASD model of the euler basis motion. 

He states 
    - "if the DOFs are independent (which maybe they are, and maybe they are not), then using the quadruture sum of the ASDs, (1), is a reasonable thing to do." and 
    - "I think this difference [between (1) and (2)] not going to impact any of your calculations"

I'd not seen a comparison of these two models either at all or in a long time, every chamber + SUS combination is different, and I had the data, so I made the comparison.

I'll discuss the 6 Euler Basis plots in reverse-traditional order, because they're easiest to understand progressively that way.

YAW
This plot is uninteresting, because the BS projection matrix from CART to EUL has only one unity element, mapping RZ directly to Yaw. 
However, it lets me introduce what I'll be plotting.
In the upper panel, this shows the both models of ASDs and the underlying Cartesian components multiplied by the CART2EUL matrix element. 
As expected here, the thick black dashed ASD -- the coherent sum (2) model -- is identical to that think magenta dashed ASD -- the incoherent sum model (2).

The lower panel is the ASD ratio of the linear sum (2) divided by the incoherent sum (1).
Of course, for this DOF, the two models are identical, so this ASD ratio is identically 1.0 across the whole frequency band.
With me so far? Good. :-P

PITCH
Here, because the Beam Splitter suspension is mounted in the center of the ISI BS optical table, yaw'd 45 degrees, RX and RY map to PITCH via sqrt(2) with the same sign.
But the RX and RY performance of the ISI BS is slightly different, so the ratio between (2) and (1) is interesting.
Most notably around the HEPI cross-beam foot resonance (traditionally called the "HEPI Pier resonance" prior to 2014; see LHO:13505) -- the broad feature at ~7 Hz -- where the ASD ratio shows that the incoherent sum model (1) under predicts Sus. Point displacement by a factor of ~1.35x w.r.t. the coherent sum model (2).
And then at some other feature at ~17 Hz, the incoherent sum model (1) is over predicting the Sus. Point displacement by ~(1/0.8) = 1.25x.

ROLL
OK, now flip the sign of the contribution of RY, and watch the coherent sum drop -- fascinating! The contribution of that same ~7 Hz feature is now dramatically over-predicted by the incoherent sum, by a factor of ~(1/0.4) = 2.5x. Are these two the inverse of each other? No! I don't show it explicitly, but comparing (2)/(1) for roll (the inverse of what's plotted) and (1)/(2) for pitch, the 7 Hz number is 0.74x and 0.52x respectively, so markedly different!  

VERTICAL
Now we're getting really interesting -- for vertical, Z is mapped one-to-one, but RX and RY are contributing in opposite sign, and with only *roughly* the same magnitude [m/rad] CART2EUL coefficient.
The incoherent sum (1) is overestimating the vertical displacement by as much as a factor of ~(1/0.2) = 5x where the vertical motion is limited by RX and RY between 0.5 and 3 Hz.
Wow!
I won't look type thru the rest of the plot, because the plot describes it best, but boy is it more interesting than I thought it would be.

TRANSVERSE
With transverse, even though this degree of freedom "doesn't matter" for the beam splitter, now we're cooking with 5 contributing Cartesian degrees of freedom and except for RZ they're all contributing at interesting levels.
Again, you reading the plot is more useful than me describing it here, but it's quite interesting that the linear sum (2) predicts more motion between 0.6 Hz and 3.5 Hz and the incoherent sum (1) predicts more motion overestimates the motion between 3.5 to 15 Hz.

LONGITUDINAL
Finally, the DOF we work the hardest on, shows contribution from all 5 Cartesian degrees of freedom. A lucky-coincidence perhaps, but it looks like the models are about the same for most of the frequency region, and the incoherent sum (1) is over-predicting the displacement between 3.5 to 15 Hz, which is re-enforcing Brian's comment.

WHAT DOES IT ALL MEAN?
Brian is, again, definitely right to call out that the linear sum (1) model is a better model of the displacement of the Sus. Point than the incoherent sum.
But, both I (and perhaps even he) definitely wasn't expecting factors of 2x discrepancy, let alone factors of 5x.
So, I think I might make Brian's conclusion from LHO:83473 a little stronger -- the difference between models will impact the calculations of the Bigger Beam Splitter Suspension (BBSS) performance, so for the update to the seismic input motion, I'll *not* just update the performance from the ~2005 seisBSC.m estimate to the current 2025 real *cartesian* performance incoherently projected to the Sus Point, but instead update it to the current 2025 real *euler* Sus. Point performance computed in the front-end.

Jennie W, Sheila

Summary: We altered the offsets on the H1:ASC_OMC_{A,B}_{PIT,YAW} QPDs which are used to align the beam into the OMC. This was aiming to give us a improvement in optical gain. After doing this we aimed to measure the anti-symmetric port light changing as we chnage the darm offset. We are trying to use both these measurements to narrow down where we have optical loss in that could be limiting our observed squeezing. Performed both measurments successfully but the different alignment of the OMC made the squeezing less good so Camilla (alog #83009) needed to do some tuning.

Last time (alog #82938) I did this I used the wrong values as our analysis used the output channels to the loops instead of the input channels which come before the offsets are put in. The new analysis of our measurement of the optical gain as seen by the 410Hz PCAL line, changing with QPD offset, shows that we want the loop inputs to change to:

H1:ASC_OMC_A_PIT_INMON to 0.3 -> so we should change H1:ASC_OMC_A_PIT_OFFSET to -0.3

H1:ASC_OMC_A_YAW_INMON to -0.15 -> so we should change H1:ASC_OMC_A_YAW_OFFSET to 0.15

H1:ASC_OMC_B_PIT_INMON to 0.1 -> so we should change H1:ASC_OMC_B_PIT_OFFSET to -0.1

H1:ASC_OMC_B_YAW_INMON to 0.025 - so we should change H1:ASC_OMC_B_YAW_OFFSET to -0.025

We stepped these up in steps of around 0.01 to 0.02 while monitoring the saturations on OMC and OM3 suspensions and the optical gain, both to make sure we were going in the correct direction and that we were not near to saturation of the suspensions as hapenened last time I tried to do this.

Attached is the code and the ndscope showing the steps on each offset, (top row left plot, top row center right plot, second row left plot, second row center right plot). The top stage osems for OM3 suspension are shown in the third row left plot, the top stage osems for OMC suspension are in the third row center left plot, and the optical gain is shown in the third row right plot.

The optical gain improved from by 0.0113731 from a starting value of 1.00595, so that is an improvement of 1.13 % in optical gain.

Around 19:04:28 UTC I started the DARM offset step to see if the change in optical gain matches that we would see if we measured the throughput of HAM 6. Unfortuntely I forgot to turn off the OMC ASC which we know affects this measurement of the loss. We stood down from changing the OMC and Camilla did some squeezer measurements, then I made the same mistake again the next time I tried to run it (d'oh). Both times I control-C'd the auto_darm_offset.py form the command line which means the starting PCAL line values, and DARM offset had to be reset manually before I ran the script successfully after turning the OMC ASC gain to 0 to turn it off.

The darm offset measurement started at 19:20:31 UTC. The code to run it is /ligo/gitcommon/darm_offset_step/auto_darm_offset_step.py

The results are saved in /ligo/gitcommon/darm_offset_step/data and /ligo/gitcommon/darm_offset_step/figures/plot_darm_optical_gain_vs_dcpd_sum.

From the final plot in the attached pdf, the transmission of the fundamental mode light between ASC_AS_C (anti-symmetric port) DCPD is (1/1.139)*100 = 87.8 %. We can compare this to the previous measurement from last week with the old QPD offsets to see if the optical loss change matches what we would expect from such a change in optical gain.

Jennie W, Sheila

Today I got a chance to redo some of my output chain measurements (alog #82555) that gave us a confusing result when we were heating up and cooling down the OM2 heater. The confusiong was that our optical gain got better for cold OM2 compared to hot, but the loss through HAM6 predicted by stepping the DARM offset and comparing it to the power at the anitsymmetric port predicted that the loss was worse with cold OM2 and gave us unreasonably low (~65 %) throughput estimate for the fundamental TM00 mode through HAM6. We realised that the OM3 and OMC alignment are being changed by the ASC during this time so that could be affecting the comparison.

Steps:

Turn off OMC ASC at 18:43:00 UTC.

Run auto_darm_offset_step.py from /ligo/gitcommon/labutils/darm_offset_step at 18:45:01 UTC.

Results: P_AS = 62.996 mW + 1.162 * P_DCPD

This makes the throughput estimate for the TM00 mode through HAM6 to the DCPDs to be 86.0 % of the power at the AS port. Which seems more reasonable than the 65% we got last time. We need to do this measurements again when we have improved kappa C somehow to check it gives us the same loss estimate between two times.

We were then going to purposely change kappa C as a comparison to the estimate the DARM offset step gives us, byt changing the QPD offsets based on this measurement 82383(I got the sign wrong last time I did this).

I turned the OMC ASC back on before doing this, however when I changed the H1:ASC-OMC_A_PIT_OFFSET to 0.45 this saturated the OM3 suspension so this was set back to nominal.

I think I got signs wrong yet again so we will try what we now think are the correct ones another commissioning period but maybe do it slowly so as not to cause saturations.