Created new OSEM estimator fits for PR3 Pitch and Yaw

This logpost is a follow up to the executive summary on PR3 OSEM estimator Filter and Blend design [LHO: 86563]

Oli took the measurements needed to commission the PR3 OSEM estimator in P and Y [see LHO: 86459]. The P measurements were taken with all M1_DAMP gains at -1, except for M1_DAMP_P, which was set to -0.2. Similarly, Y, All M1_DAMP gains were -1, except for M1_DAMP_Y, which was set to -0.2.

Ivey and I used her vectfit3 scripts to fit the transfer functions. The fits were committed to the SUS SVN under revision 12616. They live in 'sus/trunk/HLTS/Common/FilterDesign/Estimator/'

We made a few minimal changes to the original output from vectfit to match our expectation of the plants:

• Vectfit3 does a fantastic job at fitting the M1 drive to M1 transfer functions [see for example the first attached image]. However, to do so, it often adds a pair of high-frequency right-half-plane zeroes to match the phase delay that comes from the anti-aliasing filter that's a part of the TF measurement process. We often remove these zeroes entirely from the fit. This results in fits that look like the yellow trace in the first attached figure.
• We ensured that all zeroes on the fitted M1 drive to M1 transfer functions are in the left half of the complex plane. This is because we don't want to risk creating right-half-plane poles if we increase the gain of the damping through the estimator path.
• The Suspoint P and Suspoint L to M1 P transfer functions are expected to have 1 or 2 pairs of right-half-plane zeroes. In this case, we worry much less about the risk of creating unstable poles because these transfer functions are relevan in feedfordward-type paths only. Therefore, we tend to leave the zeros where vectfit3 places them.

The images of the resulting filters, together with the data that Oli took are summarized in the attached pdfs.

In order of appearance, the zpk of the fits are:

 

Suspoint Y to M1_DAMP_Y fit

    'zpk([-0.012+20.621i,0,0,-0.012-20.621i,-0.012+11.426i,-0.012-11.426i],[-0.218+6.292i,-0.218-6.292i,-0.382+14.697i,-0.382-14.697i,-0.226+21.579i,-0.226-21.579i],-0.001)'

M1 drive Y to M1_DAMP_Y fit

    'zpk([-0.024-8.341i,-0.024+8.341i,-0.011+19.405i,-0.011-19.405i],[-0.088+6.403i,-0.088-6.403i,-0.115+14.485i,-0.115-14.485i,-0.069+21.379i,-0.069-21.379i],13.34)'

 

Suspoint P to M1_DAMP_P fit

    'zpk([-2.428-2.295i,-2.428+2.295i,-0.795-9.324i,-0.795+9.324i,-0.011-22.26i,-0.011+22.26i,0.034-5.811i,0.034+5.811i,0.382-13.672i,0.382+13.672i,1.168-1.459i,1.168+1.459i],[-0.507-1.499i,-0.507+1.499i,-0.395-10.253i,-0.395+10.253i,-0.204-4.167i,-0.204+4.167i,-0.141-4.759i,-0.141+4.759i,-0.13-13.137i,-0.13+13.137i,-0.066-22.16i,-0.066+22.16i],-0.001)'

Suspoint L to M1_DAMP_P fit

    'zpk([-0.773-7.242i,-0.773+7.242i,-0.635-18.11i,-0.635+18.11i,0.301-20.227i,0.301+20.227i,1.062-6.916i,1.062+6.916i,-99.035,-0.197,0.331,45.41],[-1.293-19.638i,-1.293+19.638i,-0.33-10.141i,-0.33+10.141i,-0.289-13.191i,-0.289+13.191i,-0.162-4.1i,-0.162+4.1i,-0.122-4.732i,-0.122+4.732i,-0.087-22.103i,-0.087+22.103i],0)'

M1 drive P to M1_DAMP_P fit

    'zpk([-0.339-4.576i,-0.339+4.576i,-0.031-21.157i,-0.031+21.157i,-0.009-5.455i,-0.009+5.455i],[-0.298-13.183i,-0.298+13.183i,-0.205-4.126i,-0.205+4.126i,-0.138-4.803i,-0.138+4.803i,-0.092-22.128i,-0.092+22.128i],80.907)'

Tuesday Ops Maintenance Day Report

TITLE: 08/26 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 152Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY:
We tried to run an Initial_ Alignment but SRC aligning didn't work because the New Whitening Chassis or cable that was installed had an issue.
NLN @ 21:14:27 UTC
Back to Observing by 21:20:06 UTC

21:52 UTC Tyler started pushing his rocks around with the tractor over at the far end of the Staging building.
22:50 UTC Tyler's tractor work has lost traction with the commissioning crew and there will be no more tractoring rocks around while locked.

LOG:                                                                                                                                                                                                                                  

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:03	FAC	Erik	EY	No	Changeing Presure release valve	15:38
15:04	FAC	Randy	LVEA	N	Forklifing from LSB to OSB	15:46
15:06	VAC	Jordan	HAM Shaq	N	Gauge work in FTCE	19:06
15:10	wFAC	Chris	EY	N	Filter Checks	16:20
15:14	FAC	Kim & Nellie	LVEA	N	Technical Cleaning.	17:44
15:16	VAC	Travis & Janos	Mid Y -> Mid X	N	Getting tools from Mid Y then heading to Mid X	23:26
15:17		Richard	LVEA	N	Measure Viewport Simulator	15:26
15:22	FAC	Tyler & Beaver Bark	Staging Bld	N	Dumping rocks from a Dump truck, & Moving gravel with tractor	17:20
15:27	FAC	Randy & Mitchel	LVEA	N	Working on Clean room	15:46
15:31	EE	Fil	LVEA HAM 6&7	N	SUS & IOC rack cable racks	18:56
15:33	3IFO	Tyler	LVEA & ES	N	3 IFO checks	16:03
15:37	LN2	NORCO	Both Mid X&Y	no	Liquid Nitrogen refill	17:30
15:45	SPI	Jeff	Optics lab	N	Dropping off parts	15:46
15:45	SUS	Rahul	End Station	N	SUS Charge measurements.	18:26
15:51	FAC	Randy	LVEA	N	Cleaning off Emod in West bay	17:51
15:52	EE	Marc	LVEA	N	Helping Fil with IOC & SUS racks	18:56
16:21	VAC	Jordan , Gerardo, Anna, Mitchel	HAM Shaq	N	FTCE Gauge work & a lil Craning, Mitchel Out early	19:08
16:32	FAC	McCarthy	LVEA	N	Joining Randy	16:50
16:53	FAC	Chris	End & Mids X&Y	N	Checking phones	16:08
17:05	FAC	Eric	HAM Shaq	N	Planning a 120V Electrical Run	17:24
17:20	PEM	SAM	LVEA + Y Arm	N	Checking accelerometers.	17:33
17:24	ISC	Keita	LVEA ISC Racks	N	Checking Cable Lengths at eh ISC racks	18:56
17:25	FAC	Nellie	EY	N	Technical Cleaning	18:52
17:29	FAC	Kim	EX	N	Technical Cleanin	18:52
17:47	FAC	Eric	EY	N	Moving an extension cord	18:08
17:53	SEI	Jim	LVEA HAM1	N	HAM1 SEI Injections	18:58
18:17	FAC	Richard	LVEA Input arm	N	measuring the distance from the floor to Ceiling	18:45
18:17	PEM	TJ	HEPI Mezz	N	Setting up Dust Mon	19:08
19:56	ISC	Daniel	LVEA	N	Checking whitening chass for AS_C issues	20:21
20:14	ASC	Daniel	LVEA	N	Swapping ASC Whitening chassis	20:21

OPS Eve Shift Start

TITLE: 08/26 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 5mph Gusts, 2mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.09 μm/s
QUICK SUMMARY:

IFO is in NLN and OBSERVING as of 21:14 UTC

IFO is still behaving. Expecting a quiet shift.

H1 SUS SR3 M1 Pitch and Yaw Estimator: According to ASC -- Missing L to P Sus. Point Contribution Restores Damping on 0.64 and 0.75 Hz Mode

J. Kissel

After today's H1 SUS SR3 Pitch Estimator's inclusion of the Sus. Point L to M1 P feed forward from the HAM5 ISI GS13s (where we had mistakenly only installed Sus. Point P to M1 P) -- see LHO:86567, I now compare the times of ASC signals (using 0.02 Hz binwidth, 64 sec FFT chunks, 30 averages, and a Hanning window with 50% overlap):
    2025-08-20 18:29 UTC - Both P and Y Estimators are OFF 
    2025-08-24 18:18 UTC - Both P and Y Estimators are ON, but for the P estimator, only the Sus. Point P to M1 P contribution is included in the GS13 FF
    2025-08-26 22:00 UTC - Both P and Y Estimators are ON, and for the P estimator, both P to P and L to P contributions are included in the GS13 FF.

I'm showing only the control signals, and only the ASC DOFs which are impacted by SR3: DHARD, MICH, SRC1, and SRC2; both pitch and yaw.

In All DOFs, the 0.64 and 0.75 Hz modes that had been made worse with only the P to P model of suspension point contribution have now been restored to no-estimator levels.
In some DOFs, the 1-10 Hz broadband motion is just barely improved, but enforces the conclusion that SR3 is only partially, if not 'not the dominate contribution' to the ASC signals. 
Here's a fun one for you -- look at SRC2 Y CTRL -- and look at how much the SRC2 *yaw* motion has changed from including the *longitudinal* suspension point contribution to M1 *pitch* top mass. #ThrowsHandsInAir

But -- overall -- with the improvements and all design intent included -- the SR3 P and Y estimators slightly improve the ASC noise from 1 to 10 Hz. Great!

As Oli notes in LHO:86551 comparing all of these different configurations from totally different days and times is dubious. We'll get "official" versions of all of these ON vs. OFF configurations on Thursday 8/28.

I also attach the local estimator metrics for pitch described in LHO:86553, comparing "only Sus Point P to M1 P modeled contribution" against "P to P and L to P sus point to M1 contribution." That similarly shows that L to P contribution forms a good fraction of the signal needed for damping.

Blend filters for PR3 P and Y estimators

This logpost is a follow up to the executive summary on PR3 OSEM estimator Filter and Blend design [LHO: 86563]

Edgard, Brian, Ivey.

We used Brian's scripts to generate the blends for the PR3 OSEM estimator. We tuned these blends to the specific resonances of PR3 (which we expect to differ from SR3, as explored by Oli in [LHO: 86554]. We emphasized trying to match the bumps in the OSEM filter with the various resonances of the M1 to M1 plant [see in the figures attached].

The scripts used to create the filters, together with a script to load them into foton were updated to the SUS SVN inside 'sus/trunk/HLTS/Common/FilterDesign/Estimator'.

For pitch:
The pitch blends were created using 'blend_PR3_pitchv2.m' (see first pdf attached). The filters follow the same design principle as Brian did in [LHO: 86510] and [LHO:86452]. The blends are created by making the OSEM bandpass by adding an overall low-pass filter with four low-Q bumps  that match the observed resonanced of the M1 to M1 plant. The high-frequency gain of this filter does not asymptote to zero to keep the phase of the bumps close to zero at the resonances of the modeled PR3 M1 to M1 plant, while not creating a zero in between bumps.
The zpks are:

model_filter =

    'zpk([-0.083+22.156i,-0.083-22.156i,-0.097+13.118i,-0.097-13.118i,0,-0.037+4.136i,-0.037-4.136i,-0.045+4.738i,-0.045-4.738i],[-0.188,-0.171+4.106i,-0.171-4.106i,-0.199+4.771i,-0.199-4.771i,-0.438+13.125i,-0.438-13.125i,-0.37+22.177i,-0.37-22.177i],0.9)'

osem_filter =

    'zpk([-1.807+20.726i,-1.807-20.726i,-2.733+10.99i,-2.733-10.99i,-8.429,-0.227+4.431i,-0.227-4.431i,-1.381+2.186i,-1.381-2.186i],[-0.188,-0.171+4.106i,-0.171-4.106i,-0.199+4.771i,-0.199-4.771i,-0.438+13.125i,-0.438-13.125i,-0.37+22.177i,-0.37-22.177i],0.1)'

 

For yaw:
For the yaw estimator, we used 'Estimator_blend_skinnynotch_PR3yaw_20250825.m'  which follows the design procedure on [LHO: 86265]. In this case the procedure is more similar to designing blends for the ISI: we pick a rolloff for the Highpass (model filter) and Lowpass (OSEM) filter, but add a few notches onto the model filter. Then by using the SEI SVN function 'maketruecomplements_tol' they are turned into complementary blends.  The advantage of this process is that we can ensure the OSEM filter rolls off at high frequencies. One disadvantage is that it is a bit harder to tune the amplitude and phase of the OSEM blend around the suspension resonances.
The zpks are

model_filter =

    'zpk([-0.306+21.389i,-0.306-21.389i,-0.242+14.516i,-0.242-14.516i,-0.128+6.404i,-0.128-6.404i,0],[-1.528-21.337i,-1.528+21.337i,-1.21-14.467i,-1.21+14.467i,-0.641-6.374i,-0.641+6.374i,-0.628],1)'

osem_filter =

    'zpk([-0.81-18.387i,-0.81+18.387i,-0.473-9.928i,-0.473+9.928i,-0.216-3.503i,-0.216+3.503i],[-1.528-21.337i,-1.528+21.337i,-1.21-14.467i,-1.21+14.467i,-0.641-6.374i,-0.641+6.374i,-0.628],6.034)'

H1 ISI CPS Noise Spectra Check - Weekly

FAMIS26547

Script reports ETMX_ST1_CPSINF_V2 is high. HAM3 H2 also seems high.

LVEA Swept

I unplugged two unused extension chords and I also unplugged what is labeled as the PCALX camera computer, but it is really the the computer to take pictures of ITMX from the spool. The computer is off and not being used, so I unplugged it. I turned the lights off as I left.

H1 SUS PR3 Pitch and Yaw Estimator: Installed and Run for 1 hour

J. Kissel, E. Bonilla

Thanks to the hard and quick work of the Stanford team overnight designing blend filters and super sensor model filters (LHO:86563), I was able to install everything needed to get the H1SUSPR3's estimator up, running, and functional this morning. After having run it for bit during maintenance (and thus corner-station sensor correction was off), I've turned the "use OSEMs or use Estimator" switch to "use OSEMs" such that the SUS is performing in a functionally equivalent way as "no estimator." We'll run like this until (a) I make some plots analyzing the performance and (b) Until Thursday's commissioning period when we're in nominal low noise, so we can do similar ON vs. OFF comparisons with ASC as our metric.

The P and Y estimators were ON from 2025-08-26 18:05 UTC to 19:00 UTC.

Some extra design points beyond whats made in LHO:86563, with the mind-set of "can we 'just' copy and paste SR3's filters into PR3?"
In short: No.
In long: 
    The existing OSEM-only damping is different -- all SR3's damping loop's overall EPICs gain is -0.5, where PR3's is -1.0. This is demonstrated by LHO:86554, that means the damped M1 drive to M1 response "damped plant" is different. Namely, on resonance, the loop suppression 1/(1+G), is different because G is different, and thus P/(1+G) is different. This has the effect of shifting the fundamental mode frequencies and changing the residual Q. *That* means two things:
    (1) that the OSEM vs. Estimator blend filters -- which are relatively tight notches around resonances -- in principle, should be different. That being said, depending on the performance we end up getting we could *see* if making the blend filters generically wide enough would work. But, for now, we err on the side of "let's make the blend filters specific" because we have the measurements and the person power.
    (2) The "undamped plant" measurements for the estimator -- which are really "lightly damped" plants with whatever loop suppression is left from the broadband OSEM damping that's still always used; an EPICs gain of -0.1 for SR3 and -0.2 for PR3's damping loop controllers -- are different. So, the filters that are modeling that response -- the Sus. Point drive to M1 response filters and the M1 drive to M1 response filters -- will also necessarily be different. However, the differences are almost entirely resonance shifts and Q changes that are proportional to the differences in 1/(1+G) of the light damping (one with scaled with G = -0.1 and one with G=-0.2). Said differently, so far, only the on-diagonal M1 to M1 transfer functions are proving to be needed, and only the P to P, L to P, and Y to Yaw suspension point to M1 transfer functions are needed, and these are almost identical between PR3 and SR3.

I'll put a comparison of the filters and details of the installation in the comments.

Here're the comparison between the PR3 and SR3 Suspension Point to M1 response transfer functions.

These we installed using the scripts
/ligo/svncommon/SusSVN/sus/trunk/HLTS/Common/FilterDesign/Estimator/
    make_PR3_pitch_model.m     rev 12622
    make_PR3_yaw_model.m       rev 12622
which push the filters from the saved .mat files 
/ligo/svncommon/SusSVN/sus/trunk/HLTS/Common/FilterDesign/Estimator/
    fits_H1PR3_P_2025-08-19.mat    rev 12622
    fits_H1PR3_Y_2025-08-19.mat    rev 12619
(Most are at rev 12622 because the file names had differing arrangements of underscores and hyphens, so I cleaned that up before running.)

Notably -- we uncovered the oversight of missing L to P filter install in SR3 (LHO:86567) in enough time to make sure the same oversight didn't happen with PR3.

So -- PR3 has 
   - Pitch Estimator P to P, H1:SUS-PR3_M1_EST_P_FUSION_MODL_SUSP_P_2GAP, comparison plot
   - Pitch Estimator L to P, H1:SUS-PR3_M1_EST_L_FUSION_MODL_SUSP_P_2GAP, comparison plot and 
   - Yaw Estimator Y to Y, H1:SUS-PR3_M1_EST_Y_FUSION_MODL_SUSP_Y_2GAP,  comparison plot.

Here's the comparison between the M1 to M1 drive transfer functions. 

These are also installed with the same run of the scripts
/ligo/svncommon/SusSVN/sus/trunk/HLTS/Common/FilterDesign/Estimator/
    make_PR3_pitch_model.m     rev 12622
    make_PR3_yaw_model.m       rev 12622
which push the filters from the saved .mat files 
/ligo/svncommon/SusSVN/sus/trunk/HLTS/Common/FilterDesign/Estimator/
    fits_H1PR3_P_2025-08-19.mat    rev 12622
    fits_H1PR3_Y_2025-08-19.mat    rev 12619
(Most are at rev 12622 because the file names had differing arrangements of underscores and hyphens, so I cleaned that up before running.)

Here's the comparison between the blend filters.

Because I want to have a bit more conversation about this, I show the comparison in detail for each PIT and YAW, and when showing them all together, I show both zoomed in and out in frequency.

Namely: The pitch super sensor blend filter magnitude tops out at 0.9 rather than the traditional 1.0 for a complimentary blend filter. As Brian briefly mentions in his design aLOG (LHO:86510) this because he is mindful of the phase of the sum of this filter and its compliment. The pitch super sensor blend filter was designed to be 
    (SS Blend) = 1 - (OSEM Blend). 
In his design aLOG, he phrases it as "The low-pass [OSEM Blend] is a zero-pole pair so that it levels off to a transmission of 0.1. This is so the gap between the two [0.64 and 0.75 Hz] resonant peaks [which were designed as separate, single z:p pairs] will be well behaved. [The pairs] will cross at about 180 degrees of phase shift and make a sharp zero [between resonances], and [that] deep zero seemed to be causing numerical issues when Oli was implementing the yaw blends. The flat bottom at 0.1 prevents that."
     
    So, if you force the OSEM blend to bottom out at 0.1, then the super-sensor blend will top out at 1 - 0.1 = 0.9.

    This, in effect, sacrifices 10% loop gain for numerical stability.

    Brian says he's working on a -v3 design that might improve this.
    Honestly, I think it's probably fine from an overall loop gain perspective -- I guess this can be rectified by increasing the estimator control filter by 10%, but even if not, 10% less damping is totally fine.

    If loop or numerical stability demands that we can't increase the overall gain can we augment this design such that *well* above the 0.64 and 0.75 Hz resonances -- can we still roll off the OSEM contribution? Say, multiply the whole -v2 OSEM filter by a high-pass at, 10 Hz (and then adjust the SS blend accordingly to keep things complimentary)?

Data Quality Shift Report: LHO 2025-08-18 to 2025-8-24

Link to report here.

Summary:

• Very quiet week with long ranges of observing/lock. 56.57 hours locked from Sunday to Tuesday, and 41+ hours Observing from Sat to Mon!
• Average of 78.1% observing -- 87.7%, 40.8%, 80.7%, 72.1%, 76.8%, 88.6%, 100% per day
• Range stayed around 150-155 Mpc throughout week. Noted large, fast dips in range on Tuesday, Thursday, and especially Sunday around 0200 UTC (7:00 PM PDT). While Tuesday did correlate to anthropogenic causes (fire hydrant issues), I was unable to find a correlation for Thursday or Sunday. Did not notice noise in h(t). 
• Increased violin modes (specifically ~500 Hz) following commissioning, as noted in the Tues EVE Ops Shift Summary (aLog_86465). I noted that these continued throughout the week, with the most extreme being on Thursday. 
• Lowest FScan lines on Tuesday with ~2100 lines and highest on Sunday with ~2800 lines.
• Repeat Round Winners: Wed, Fri, Sat, Sun: H1:ASC-Y_TR_A_NSUM_OUT_DQ; Tues and Sun: H1:ASC-Y_TR_B_NSUM_OUT_DQ; Sat and Wed: H1:ASC-Y_TR_A_YAW_OUT_DQ; Thurs and Wed: H1:ASC-Y_TR_A_PIT_OUT_DQ

Apologies for the delay in posting. I was having difficulty loading the aLog website & summary pages yesterday and wanted to follow up on some suggestions from the DetChar call.

Range diff over last 24 hours

I compared the sensitivity from two segments over the last 24 hours where our range was about 157 Mpc and 162 Mpc each (60 second averages). Looks like a broad improvement from about 30-300 Hz when using the range comparison script.. The 350 Hz SQZ blrms are 0.25 dB better in the higher range time. It's hard to see a large change in the 38-60, 60-100 or 100-450 Hz range blrms. Whether you use a shorter or longer average, the difference between two times is 5 Mpc.

Whitening chassis for ASC-AS_C and OMC-REFL_A changed

This continues work from alog 86442. A new cable, D2500252, was made to replace the old ISC_455 (D2200327) and ISC_39 (standard 25-pin d-sub cable).

The DC offset have been adjusted but not accepte din SDF.

The second anti-whitening filter of OMC-REFL_A is now a normal anti-whitening filter, zpk([10],[1],1,"n"), and not the antiLP, zpk([49.63],[497.5],-0.9995,"n"). However, the filter files are not updated yet.

Changing TCS-SIM values for surface defocus effects

M. Todd, C. Compton, S. Dwyer

---

We changed the gain settings in TCS-SIM that convert the powers of each actuator (including self-heating) to surface defocus for calculating the overall radius of curvature of each test mass at a given thermal state.

The motivation for this was that the simulation seems to be largely overestimating the Higher Order Mode spacing. Hopefully, with these new predictions, we will observe better agreement between the simulation and HOM measurements.

We also changed the absorption values using values taken from alog 80714 for the ITMs, and using galaxy for the values for the ETMs.

 

Tuesday Ops Maintenance Day

TITLE: 08/26 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 15mph Gusts, 9mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.09 μm/s
QUICK SUMMARY:
H1 has been locked for 10+ hours.

Today At 14:21 UTC it appears the Magnetic Injections started.
At 14:40 UTC Back to Observing.
Down to Commissioning again at 14:45 UTC



Expected Tuesday Maintenance Work:
VAC - MX and MY pump install work continuing (booster pumps will be connected)
VAC - BSC1 AIP troubleshooting. Needs LASER SAFE condition.  Postponed
VAC - LN2 delivery: MX (CP5) and MY (CP3)
VAC - FC guage work (pumping)
Randy - North Bay - cleaning of top of eMod
Randy - East Bay - remove C3 cleanroom sock cover over HAM5 & 6
FAC - rock delivery at Staging building
CDS -Daniel - Change the whitening chassis that is currently used for the ASC-AS_C QPD
Fil - HAM5&6 racks - install of BHD stuff
LN2 - MY & MX
Charge meas't ?

 

 

Correction/Update: SR3 Estimator Impact on ASC (plus new OMC and ASC-AS plots)

Jeff, Oli

On Thursday (86507) I alogged the differences we were seeing in the ASC with the SR3 estimator on. The time that I was taking as our 'reference time' for the estimator off, however, doesn't seem like it was a good time showing the lowest the ASC noise could be. You could say this caused us to over estimat(or) the differences.
So I plotted some more times with the estimator off, then with the estimator on, and I found that maybe the SR3 noise is limiting the ASC noise less than shown in 86507. However, I also found that below 0.2 Hz, where we thought that the estimators were elevating the noise, that also seems to have been not related to the estimator, so that is something we might not have to worry about. 
Of course the peaks at 0.6 and 0.7 Hz are elevated in the estimator plots below due to not damping them in the inital blend filter (mentioned in 86507), and this is something that we partially fixed this morning (86544), and will be working on further damping at the next available commissioning time.

There are still times where the estimator on makes the noise better at some frequencies, but there are also other times where the estimator is on, but something else is limiting the noise, so it looks like SR3 isn't limiting the noise very much at all. It will still be interesting to see if adding estimators onto the rest of the SRC give us different results.

In the plots below, I am showing the variation in noise with the estimators off and the estimators on,
The 'bad' time for the estimators OFF is: 2025-08-17 09:00 UTC (green)
The 'good' time for the estimators OFF is: 2025-08-20 18:29 UTC (blue)
For the estimators ON times, they're both 'good' and 'bad' at different frequencies, so I'll just list their times:
2025-08-21 16:35 UTC (red)
2025-08-24 18:18 UTC (gold)

	Pitch			Yaw
ASC-DHARD	Error
	Est OFF	Est ON	Both	Est OFF	Est ON	Both
	Control
	Est OFF	Est ON	Both	Est OFF	Est ON	Both
ASC-MICH	Error
	Est OFF	Est ON	Both	Est OFF	Est ON	Both
	Control
	Est OFF	Est ON	Both	Est OFF	Est ON	Both
ASC-SRC1	Error
	Est OFF	Est ON	Both	Est OFF	Est ON	Both
	Control
	Est OFF	Est ON	Both	Est OFF	Est ON	Both
ASC-SRC2	Error
	Est OFF	Est ON	Both	Est OFF	Est ON	Both
	Control
	Est OFF	Est ON	Both	Est OFF	Est ON	Both
ASC-AS_A_DC	Control
	Est OFF	Est ON	Both	Est OFF	Est ON	Both
ASC-AS_B_DC	Control
	Est OFF	Est ON	Both	Est OFF	Est ON	Both
ASC-OMC_A	Control
	Est OFF	Est ON	Both	Est OFF	Est ON	Both
ASC-OMC_B	Control
	Est OFF	Est ON	Both	Est OFF	Est ON	Both

OMC-DCPD_SUM_OUT	Est Off	Est ON	Both
OMC-REFL_A_LF_OUT	Est Off	Est ON	Both

 

Elenna's new SRCL FF Fit turned on

In 86481, Elenna proposed using a new FF fit as the bruco showed SRCL coherence, this has improved the low frequency SRCL noise, but moved the bump at 200Hz to 100Hz, overal a small improvement, see plot attached. Saved in ISC_LOCK and safe and observe sdfs.