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Reports until 22:02, Tuesday 01 September 2015
H1 General
cheryl.vorvick@LIGO.ORG - posted 22:02, Tuesday 01 September 2015 (21125)
Control Room FOMs updated and files converge in a directory that's backed up

What started out as a fix for the PRMIsb.stp that was losing POP_A_LF_OUTPUT off the top of the strip tool plot, revealed an inconsistent mess.

In the ops directory, there was a PRMIsb.stp, except that is was now only a symbolic link to IfoLock.stp.  This was running on a front screen in the Control Room.

In the scripts directory, there was  a PRMI.stp that had the issue with POP_A going off the top of the plot. This was running on a side screen in the Control Room.

I updated the scripts directory PRMIsb.stp file, loaded it on both of the Control Room screens, and deleted the ops PRMIsb.stp and IfoLock.stp files.

I committed the scripts directory PRMIsb.stp file to svn.

Images attached to this report
H1 CDS (CDS)
jonathan.hanks@LIGO.ORG - posted 17:57, Tuesday 01 September 2015 (21120)
Wiki entry on the DMT to EPICS bridge
As this is a new IOC and setup I have started a wiki page in the cds wiki with a overview of the dmt to epics ioc system we set up today. https://lhocds.ligo-wa.caltech.edu/wiki/DMT2EPICSIOC.
H1 ISC
kiwamu.izumi@LIGO.ORG - posted 17:19, Tuesday 01 September 2015 (21118)
relocking today

We were able to be back to full lock at around 17:00 UTC. There were a couple of notable points as listed below:

H1 CAL (CAL)
craig.cahillane@LIGO.ORG - posted 17:18, Tuesday 01 September 2015 - last comment - 23:05, Tuesday 08 September 2015(21110)
ER8 Preliminary Strain Uncertainty Carpet Plots

C. Cahillane, D. Tuyenbayev I have updated the strain uncertainty calculator to use Darkhan's latest ER8 model along with ER8 data.

The ER8 model: /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/ER8/H1/Scripts/DARMOLGTFs/H1DARMOLGTFmodel_ER8.m

The ER8 params: /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/ER8/H1/Scripts/DARMOLGTFs/H1DARMparams_1124597103.m

The ER8 uncertainty calc: /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/S7/Common/MatlabTools/strainUncertaintyER8.m

Again, there are slight discrepancies between Plot 1 and Plot 7. To reiterate, Plot 1 uses the full O1 calibration method and real data, while Plot 7 uses the Inverse Response TF with no data:

Plot 1:

dh = DARM_ERR / C_true + A_true * DARM_CTRL

     ------------------------------------

     DARM_ERR / C_0 + A_0 * DARM_CTRL

Plot 7:

dh = (1 + G_true) / C_true

     ----------------------

        (1 + G_0) / C_0

This time, I believe the discrepancies are a result of the as-of-yet incomplete ER8 model.  I will rerun this test when Kiwamu, Jeff, and Darkhan have all finished updating the ER8 model.

Note that the ugly spikes in uncertainty have disappeared from Plots 1-6 (as opposed to aLOG 21065). 

This is because now I do not have to interpolate my DARM_ERR and DARM_CTRL FFT frequency vector thanks to Darkhan's clever ER8 model functions par.{A,C,D,G}.getFreqResp_total(freq) where freq is a frequency vector I define.  This is possible because each portion of the ER8 model is an LTI object.  Thanks Darkhan.

Non-image files attached to this report
Comments related to this report
craig.cahillane@LIGO.ORG - 23:05, Tuesday 08 September 2015 (21324)CAL
I have updated these plots for the newly updated ER8 Calibration Model at GPS time 1125747803 (Sep 08 2015 11:43:06 UTC).
Now I am getting better agreement between the data-based strain error plot (Plot 1) and the response function error plot (Plot 7).

I am now getting a conspicuous spike in error at 37.3 Hz in Plots 1-6, which is exactly where the X_CTRL calibration line is.  I cannot be sure why this line is accounting for massive errors in the strain calculation with only 10% changes in the kappa_tst, etc...
Non-image files attached to this comment
H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 17:16, Tuesday 01 September 2015 (21116)
DAQ data corrupted after this morning's reconfiguration

Jonathan, Jim, Dave:

Details can be found in the maintenance summary below. The LHO DAQ was writing bad data to science, commissioning, second and minute trend files from 12:39 to 15:21 PDT today. Both h1fw0 and h1fw2 were affected. The data corruption is manifested as 16Hz noise on every channel (looks like channel bleed). Only frame writers are affected, so the real-time data from the NDS did not show this corruption.

The problem was quickly resolved, there is a naming restriction for INI files, they cannot end in the 7 character string "GDS.ini".  The new slow data ini file was  named H1EDCU_GDS.ini. This file was removed and the problem went away.

the attached plot shows the noise as seen in a mid station seismometer channel. One second a full data is shown

Images attached to this report
H1 CDS (PEM)
david.barker@LIGO.ORG - posted 17:12, Tuesday 01 September 2015 (21117)
PEM CS Radio Channels Renamed

Anamaria, Robert, Dave:

WP5479

h1pemcs.mdl was changed to rename the radio channels to conform with LLO names. The attachments below show the names for the 3rd ADC before and after the change. The DAQ was restarted to complete this upgrade.

Images attached to this report
H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 17:04, Tuesday 01 September 2015 (21115)
CDS maintenance summary

New Frame Writer Added To DAQ WP5455

Keith, Dave, Jim

The new frame writer was connected to the QFS file system this morning. We are still in a testing phase, so the machines don't have their final names at the moment. The MSR-QFS file system was removed from h1fw1 and added to h1fw2. The configuration for h1fw2 is to write science, commissioning, second trend and minute trend frame files (as it was when testing on local disks). The configuration for h1fw1 was changed to stop writing commissioning frames, second and trend frames. It now only writes raw-minute data files on its local SSD-RAID.

The only problem found in the transition is that with the new daqdrc configuration file h1fw1 would not start running. Comparing with the LLO file, we moved the line

to near the top of the file (line 3) and the daqd process would then run.

h1odcmaster, putting the TCS IPC channel back in WP5474

Ryan, Duncan, Dave:

The TCP IPC channel was mistakenly removed from h1odcmaster during last Tuesday's upgraded. We put the channel back in today. The model and the DAQ were restarted.

DAQ reconfigured for new EDCU files, major problem with DAQ found and fixed

Keita, Daniel, Jamie, Jonathan, Jim, Dave:

Several EDCU files were modified this morning:

These changes went in with the DAQ restart at 12:39 PDT. This afternoon Keita reported that trended data is showing large 16Hz spikes in the SUS channels he was looking at. We looked at some PEM channels as saw the same noise in the full frames, second frames and minute trends starting at 12:39. We switched our NDS from h1nds1 to h1nds0 which showed the same problems, so it was not caused by the new frame writer.

Going with a gut feeling that the addition of a new INI file could be the problem rather than expanding existing files, I removed the new H1EDCU_GDS.ini file (which contains the IR epics channel) and restarted the DAQ. The problem went away.

To prove that the problem is with the new file rather than the total number of slow channels, I added the SENSMON channel to the H1EDCU_DAQ.ini and restarted the DAQ. The data corruption problem was still absent, and we are trending the IR.

At this point we stopped making DAQ changes and went to the code. It appears that in the file daqd.cc if an INI file's name ends with the characters "GDS.ini" the code for frame builders skips a block of code. So it appears I was unlucky in choosing the name H1EDCU_GDS.ini.

To test this, next week we will create the new file but call it H1EDCU_DMT.ini to get around the naming restriction.

Removal of Partially Loaded Filters

Hugh, Dave:

several models had accumulated partial filter loads over the past week. I investigated why and then performed a full load on:

h1asc, h1calcs, h1oaf, h1susbs, h1susetmx, h1susitmx, h1susitmy, h1susprm

SUS front end ADC/DAC replacements

Dave, Jim, Richard:

h1sush56 and h1susauxh56 systems were completely powered down. h1sush56 had its first 18bit DAC card replaced. h1susauxh56 had an ADC and interface card replaced.

On power up we noticed that h1sush56 is showing a auto-cal failure on the third DAC. On a subsequent IOP restart the 3rd DAC failed autocal again. This card is used by SR3 M2 (last 4 chans) and SUSOMC M1 (RT and SD, first two channels).

H1 PEM
filiberto.clara@LIGO.ORG - posted 16:47, Tuesday 01 September 2015 (21112)
PEM Install - Radio Narrowband Antennas/Microphones/Magnotometer
- Connected the radio narrowband antennas (9MHz & 45MHz) from the LVEA/ebay to the Quad I&Q RF Demodulator chassis in the PEM rack. Cables needed from the Demod chassis to the AA PEM chassis were made today and need to be installed.
- Installed microphone at EY in the electronics room.
- Ham2 Magnetometer filer board was installed. Found conditioning box of magnetometer to be faulty and was replaced.
H1 GRD
jameson.rollins@LIGO.ORG - posted 16:47, Tuesday 01 September 2015 (21099)
New DIAG guardian nodes added to IFO top node, GUARD_OVERVIEW screen

DIAG_SDF, DIAG_EXC, DIAG_CRIT guardian nodes added to OBSERVATION READY checks

The three new guardian DIAG nodes (SDF, EXC, CRIT) have been put under the IFO top node.

This means that all three nodes must be OK before we go to OBSERVATION MODE.

As a reminder, the nodes are doing the following checks:

The OBSERVATION_OVERVIEW and GUARD_OVERVIEW MEDM screens have been updated to reflect this new information.

The OBSERVATION_OVERVIEW screen has been simplified to indicate the Guardian IFO top node is now the only thing going into the READY check.  Here is the OBSERVATION_OVERVIEW screen embeded in the GUARD_OVERVIEW top panel:

Near the bottom of the GUARD_OVERVIEW screen, the three new DIAG nodes have been added into their own box.  Each of these three critical nodes are embeded in a highlight box that is orange when the node is NOT OK:

NOTE: the DIAG_SDF and DIAG_EXC panels are actually related display buttons that open up the SDF_OVERVIEW and EXCITATION_OVERVIEW screens respectively.

Once the three DIAG nodes are OK, the orange highlights will disapear.  Once the IFO top node see that *ALL* nodes are OK, the "READY BIT" box will go from orange to green.  At that point, the operator can choose "OBSERVE" from the "INTENT BIT" button, and the entire
"OBSERVATION BIT" box will go green.

To clarify: all relevant information for OBSERVATION MODE is now described in the GUARD_OVERVIEW screen.  No other information should be needed.

Images attached to this report
LHO FMCS
bubba.gateley@LIGO.ORG - posted 16:23, Tuesday 01 September 2015 (21107)
New DCS room fire suppression system
The crew from Fire Protection Specialists arrived on site this afternoon to begin the 2nd phase of the installation. I met with them and informed them of driving procedures while on site. They will install the tank, piping and spray nozzle. The crew said they expect the work to be completed before the end of the week.


S&K electrician should be on site next week to make the final tie in.
H1 SYS
jameson.rollins@LIGO.ORG - posted 16:12, Tuesday 01 September 2015 - last comment - 18:02, Tuesday 01 September 2015(21109)
SDF_ and EXCITATION_OVERVIEW screens updated to account for different DCUIDs between sites.

We were using common SDF_OVERVIEW and EXCITATION_OVERVIEW screens between H1 and L1.  However, for some reason the sites can't agree on a common model->DCUID mapping, which makes this not possible.

These screens have been removed from the common directory (sys/common/medm) and moved to the ifo-specific directories:

If the site CDS groups can ever agree on anything we can maybe move back to using common screens.

Comments related to this report
jenne.driggers@LIGO.ORG - 17:32, Tuesday 01 September 2015 (21119)

The sitemap needs to be updated to reflect this change - SDF_OVERVIEW is not currently available from the GRD button on the LHO sitemap.

jameson.rollins@LIGO.ORG - 18:02, Tuesday 01 September 2015 (21122)

Updated sitemap.

LHO General
corey.gray@LIGO.ORG - posted 16:11, Tuesday 01 September 2015 (21087)
Ops DAY Summary

Morning:

Delayed some activities a bit this morning, so we could attempt monitoring of SR3 for glitches while in DRMI.  From about 7:55 - 8:35 I went through an alignment (since there was no DRMI locking over the night, & Richard wanted it ).  After the alignment, waited for DRMI to lock, but no luck; so started to allow planned Maintenance Activities as planned (see log below).

Afternoon:

All of the activities lined up for Maintenance were mostly completed (an item or two were not attempted).  So around 2pm is when we transitioned from Maintenance to Alignment (and then Locking).

Log of Day's Activities

H1 DCS (DCS)
gregory.mendell@LIGO.ORG - posted 16:07, Tuesday 01 September 2015 (21108)
Restart of DCS Disk2Disk and diffFrames

After maintenance DCS (LDAS) restarted these processes which read data from the CDS filesystems:

Restarted Disk2Disk copying of CDS frames to the LDAS archive and scratch filesystems: Sept 01 2015 15:18 PDT.

Restarted diff of CDS science frames: Sept 01 2015 15:59 PDT.

H1 CAL
kiwamu.izumi@LIGO.ORG - posted 15:36, Tuesday 01 September 2015 - last comment - 17:09, Thursday 30 June 2016(21101)
OMC DCPD signal chain,maybe missing 10-ish kHz pole in our model

In this morning, I checked the OMC DCPD electronics chain (for both A and B) by injecting known sine wave analog signal. This was one of those items that Keita suggested me a while ago.

According to the data, I am concluding that our calibration model needs to add another pole at 10-ish kHz for accurately simulating the OMC whitening circuits.

 


Method

The measurement method is straightforward -- it is a swept sine measurement in a manual way.

I had a function generator by the HAM6 electronics rack which drove a single-ended-to-differential convertor (D1000931, technically speaking this is a coil driver test box). Then the differential signal is sent to the input of the OMC DCPD whitening board (D1002559, S1101603) by some clipping technique. By the way, the actual cable for connecting the OMC DCPDs were unplugged during the measurement. The excitation amplitude was set to 2 Vp-p at the function generator which resulted in 2 Vp-p in both positive and negative paths at the input of the whitening board as expected accroding to the schematic of the coil driver test box.

I then recorded the data in IOP at the full sample rate using dataviewer for 1 sec for a selected excitation frequency (and for some reason, diaggui did not want to run and hence dataviewer this time). Keeping the same excitation amplitude, I manually stepped the freqyency from 8 kHz to 100 Hz. After every step, I saved the time series of the IOP so that I can make a transfer function later. In addition, I had an oscilloscope with me which kept monitoring the excitation ampitude at the input of the whitening board. The scope told me that the excitation ampltude stayed constant at 2.02 Vp-p in each channel throughtout the measurement. The OMC DCPD had

 

Analysis and result

To get a transfer function from the data that I took in time series, I decided to do a sine-wave fitting for each data chunk to get the amplitude information. I wrote a small matlab script to do it. It can be found at:

aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/Matlab/OMC_DCPD_AnalogChain_TimeSeries.m

The script utilizes fminsearch and spits out the best fit amplitude for each frequency measurement. Additionally, it places uncertainty or error bar by taking the standard deviation of the residual. Note that this is not a standard way to place an error bar since it does not take the number of measurement points into consideration. According to the fit, the residuals were found to be usually a few counts which is much smaller than the amplitude of signals which was about 2000 counts. So it typically places 0.1% uncertainty after all.

The result is shown in the attached pdf. By the way the lower panel in the plot says, "residual", but it should read "(measured)/(model)" instead. It shows the measured transfer function together with the expected model transfer function for comparison. It is very obvious that the measurement suggests that our model is missing some high frequency pole. The model is merely made of the analog AA response which I have already measured and fitted. Adding some random pole, I could see an extra pole at around 10.7 kHz making the fitting much better. In fact, I sort of knew that there seemed to be a high frequency pole by some other measurements which I did not post. We probably need to add this high frequency pole in our calibration model.

Non-image files attached to this report
Comments related to this report
kiwamu.izumi@LIGO.ORG - 19:28, Tuesday 01 September 2015 (21123)

I have measured and fitted the AA filter response for DCPD A and B (ch13 and ch14 of S1102788 respectively). I used the same coil driver test box to produce differential signal and measured the transfer functions with SR785. The results don't show any unexpected additional high frequency poles.

The plots are shown below in line. The fitting is good up to 10 kHz.

 

The fitting code can be found at:

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/Liso/fit_AA_OMC_DCPD_A.fil

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/Liso/fit_AA_OMC_DCPD_B.fil

The analysis/plot code can be found at:

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/python/OMC_DCPD_AA_filters.py

The figures in both pdf and png formats are available at:

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_AA_DCPD_A.pdf

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_AA_DCPD_A.png

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_AA_DCPD_B.pdf

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_AA_DCPD_B.png

Images attached to this comment
Non-image files attached to this comment
kiwamu.izumi@LIGO.ORG - 21:24, Tuesday 01 September 2015 (21124)

Independently of the above measurements, I have measured the entire signal chain of the OMC DCPD A and B by injecting random signals from the extra DAC output in LSC (a.k.a. LSC-EXTRA_AO2).

It also showed a high frequency pole at around 10.7 kHz which is consistent with the result from the manual swept sine described above.

 


Measurement setup

  • Random noise excitation in LSC-EXTRA_AO2
  • Output of the LSC-EXTRA_AO2 at the ISC rack is connected to a spear RF patch panel and routed all the way to the HAM6 area.
  • In the HAM6 area, the excitation signal is split into two by a BNC tee and drives the A and B inputs (corresponding to ch4 and ch5 respectively) of the whitening board (D1002559, S1101603).
    • Note that this time the connections are made in a single-ended manner, so that it does not exctie the negative leg of the differential receiver in the whitening board.
  • I took a transfer function from the IOP channel of LSC-EXTRA_AO2 and that of OMC DCPD A and B in order to avoid confusion from IOP's up/down-sampling filters.

By the way, in the digital world particularly in the IOP world, LSC-EXTRA_AO2 is called DAC0_CH9, and DCPD A and B are called ADC0_CH12 and CH13 respectively.

AI filter for LSC-EXTRA_AO2 needed to be measured

Since this measurement automatically includes the AI filter for LSC-EXTRA_AO2, we need to subtract this transfer function out of the resultant measurement. So I measured and fitted it (ch10 of S1102761) by using the coil driver test box (D1000931) and a SR7850. Here is the result.

As shown in the plot above, the fitting is good up to 10 kHz. I did not see unexpected high frequency pole. The fitting code, data and results can be found at:

/aligocalibration/trunk/Runs/ER8/H1/Measurements/AAAI/LSC_EXTRA_AO_AI_v2.dat

/aligocalibration/trunk/Runs/ER8/H1/Scripts/AAAI/Liso/fit_AI_LSC_EXTRA_AO.fil

/aligocalibration/trunk/Runs/ER8/H1/Scripts/AAAI/python/LSC_EXTRA_AO2_AIfilter.py

/aligocalibration/trunk/Runs/ER8/H1/Results/AAAI/2015-08-27_AI_LSC_EXTRA_AO.png

/aligocalibration/trunk/Runs/ER8/H1/Results/AAAI/2015-08-27_AI_LSC_EXTRA_AO.pdf

This fitting result is then used in the subsequent analysis as decribed below.

 

Results

First of all, I attach the measured transfer functions together with the fitting result.

As I noted in the above subsection, the measured transfer functions include

  • AI filter of LSC-EXTRA_AO2
  • AA filter of DCPD A or B
  • flat response of the whitening filters (as I set them to 0dB with no whitening stages engaged)

In my fitting model, I newly inserted a high frequency pole at around 11 kHz as an initial guess. Without this additional high-freq pole, the fitting would be miserable above 1 kHz similarily to the one shown in the above entry or alog 21101. As for the parameters of the AA and AI filters, I have used the fitted parameters and do not try to re-fit them in this anaysis. In other words, the fitting parameters in this analysis are:

  • high-freq pole at around 11 kHz
  • scale factor (which should be close to 0.5 because I am driving only one leg of the differential receiver)
  • delay presumably due to some computation cycle

The below are the raw output from LISO:

#Best parameter estimates:
#pole6:f =  10.7609523979k +- 1.226 (0.0114%)

#Best parameter estimates:
#pole6:f =  10.7183613550k +- 1.209 (0.0113%)

The upper one represetns the fitting result for DCPD A and the lower one for DCPD B. Both of them have a pole at around 10.7 kHz.

Some SVN info

As usual, the data, codes and resultant figures are saved in svn. They can be found at:

/aligocalibration/trunk/Runs/ER8/H1/Measurements/OMCDCPDs/2015-08-27/LSC_AO_OUT_to_OMC_DCPDs_RandNoise_0whitenings.xml

/aligocalibration/trunk/Runs/ER8/H1/Measurements/OMCDCPDs/2015-08-27/IOPCH9to_IOPCH12_0whitening_tf.txt

/aligocalibration/trunk/Runs/ER8/H1/Measurements/OMCDCPDs/2015-08-27/IOPCH9to_IOPCH13_0whitening_tf.txt

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/Liso/fit_LSCCH9toOMCCH12_0whitening.fil

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/Liso/fit_LSCCH9toOMCCH13_0whitening.fil

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/python/OMC_DCPD_AAandWhite.py

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_DCPD_A_AAand0White.pdf

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_DCPD_A_AAand0White.png

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_DCPD_B_AAand0White.pdf

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_DCPD_B_AAand0White.png

 

Next step

I will analyze equivalent data with one whitening stage engaged. This is more important because this is likely going to be the configuration we will run during O1.

Images attached to this comment
Non-image files attached to this comment
kiwamu.izumi@LIGO.ORG - 23:00, Tuesday 01 September 2015 (21126)

I have measured the DCPD signal chain in the same fashion as the previous alog, but this time with the 1st whitening stage engaged.

Here is my conclusion:

  • The whitening board seems to consistently show a high frequency pole at around 11 kHz
  • The zero and pole location of the 1st whitening stage seem to be inaccurate by 12% at most
  • We should  re-measure the whitenig board in a wide frequency band

Measurement setup

The measurement setup is the same as the one in the previous alog shown above. I drove LSC-EXTRA_AO2 by random noise and took transfer functions from the IOP test point of LSC-EXTRA_AO2 to that of DCPD A and B. This time the 1st stage whitening filter is engaged with 0 dB gain.

Results

Here are the measured transfer functions with the fitting results.

LISO says:

#Best parameter estimates (for DCPD A):
#pole6:f =  10.8756718522k +- 1.275 (0.0117%)
#pole7:f =  10.3442465820 +- 4.165m (0.0403%)
#zero2:f =  992.1541013425m +- 2.461m (0.248%)
#factor =  500.1410089072m +- 1.112m (0.222%)

#Best parameter estimates (for DCPD B):
#pole6:f =  10.8295424180k +- 1.26 (0.0116%)
#pole7:f =  10.4145450914 +- 4.172m (0.0401%)
#zero2:f =  998.2444937993m +- 2.463m (0.247%)
#factor =  499.8306079302m +- 1.105m (0.221%)

 

The result suggests that the high frequency pole (called pole6 in the fitting code) moved up by 1-2% from 10.7-ish kHz to 10.8-ish kHz in both DCPD A and B compared with the previous data without the whitening filter engaged. I don't have a good explanation for why they moved up. But the point is that the high frequency pole does exist in the whitening configuration that we want to run during O1. Therefore we should definitely include this pole in our calibration model. Additionally, the measurement done at Caltech also shows a reduction in the magnitude as frequency reaches the end of the measurement frequency band at around 6 kHz (S1101603). Therefore I start believing that this high frequency pole is real and do exist in the whitening boards. I guess this effect was not visible in my intemnsity transfer function measurement (alog 20851) because ASC-AS_C, which was my intensity reference, also uses the same whitening circuit (D1001530) as OMC DCPDs.

Another interesting thing is that LISO reports different poles and zeros for the actual whitening filters than the ones reported in DCC (S1101603, or see nice summary by Koji at alog 17647). The pole location seem to be almost the same at a few % level, but the location of zeros differ by more than 10%. This is not cool. This also makes me think that we should re-measure the whitenig filter response.

SVN info

/aligocalibration/trunk/Runs/ER8/H1/Measurements/OMCDCPDs/2015-08-27/LSC_AO_OUT_to_OMC_DCPDs_RandNoise_1whitenings.xml

/aligocalibration/trunk/Runs/ER8/H1/Measurements/OMCDCPDs/2015-08-27/IOPCH9to_IOPCH12_1whitening_tf.txt

/aligocalibration/trunk/Runs/ER8/H1/Measurements/OMCDCPDs/2015-08-27/IOPCH9to_IOPCH13_1whitening_tf.txt

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/Liso/fit_LSCCH9toOMCCH12_1whitening.fil

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/Liso/fit_LSCCH9toOMCCH12_1whitening.fil

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/python/OMC_DCPD_AAand1White.py

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_DCPD_A_AAand1White.png

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_DCPD_B_AAand1White.pdf

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_DCPD_B_AAand1White.png

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-08-27_DCPD_B_AAand1White.pdf

Images attached to this comment
kiwamu.izumi@LIGO.ORG - 01:45, Wednesday 02 September 2015 (21131)

This should be a killer measurement for this long discussion which was triggered by the unexpected high frequency pole-ish behavior in the DCPD signal chain. I have measured the transfer function of the DCPD whitening filter using an SR785 tonight.

The current conclusions are that:

  • A measurement of the whitening filter tells that we need to have two poles at high frequencies-- one at around 18 kHz and the other ar around 14 kHz
    • ( In addition, another pole at 98 kHz gives us a better fitting )
  • The whitening zero-pole pairs need to be updated in the calibration model and perhaps in the OMC front end model in order to accurately compensate the filter response.

 


Motivation

There seemed to be one or perhaps multiple high frequency pole(s) at a frequency on the order of 10 kHz. We wanted to include them in the calibration model to be mroe accurately model the phase and time delay. Besides, independtly of the high frequency poles, we noticed that the whitening zero-pole pairs were not precisely at the frequencies specified in the DCC document of an early measurement (S1101603). These two things pushed us to re-measure the analog transfer function of the whitening filter, in particular the first stage which is the one we usually use in full lock.

Measurement

I again used the coil driver test box only for the reason that I wanted a single-ended-to-differential convertor. With an SR785, I performed a swept sine measurement for ch4 and ch5 which correpond to DCPD A and B respectively. The 1st stage of the whitening filter was engaged while the rest are disabled for both A and B whitening filters. The whitening gain was set to 0 dB for both A and B. These settings are nominal that we usually operate in full lock. The exctiation amplitude was 200 mVp-p in the positive and negative inputs which resulted in 2 Vp-p at highest at the positive and negative outputs. With a scope, I confirmed that there was an obvious distortion or saturation in the signal at the outputs.

Results

I fitted the measured data with four poles and one zero. See the fitting results shown below.

As shown in the plot, the fitting is good from 1 Hz to 10 kHz at 0.1% level in absolute amplitude and 0.02 deg level in the phase. Here are the raw output from LISO.

#Best parameter estimates (for DCPD A):
#pole0:f =  18.6402825833k +- 20.23 (0.109%)
#pole1:f =  14.5121291389k +- 12.5 (0.0861%)
#pole2:f =  98.9771014448k +- 60.89 (0.0615%)
#pole3:f =  10.2675781089 +- 660.2u (0.00643%)
#zero0:f =  973.9581771978m +- 151.1u (0.0155%)
#factor =  993.7495082788m +- 129.2u (0.013%)


#Best parameter estimates (for DCPD B):
#pole0:f =  18.4126906482k +- 21.61 (0.117%)
#pole1:f =  14.6312083283k +- 13.88 (0.0949%)
#pole2:f =  98.3231767285k +- 60.51 (0.0615%)
#pole3:f =  10.3405121747 +- 667u (0.00645%)
#zero0:f =  980.5696173840m +- 152.8u (0.0156%)
#factor =  993.4759822630m +- 129.8u (0.0131%)

 

In order to get a better fitting, I ended up adding three poles at high frequencies -- two of them seem to stay between 10 and 20 kHz while the third one tends to be at around 98 kHz. I did not need to have a delay at all because this is just an analog circuit.

SVN info

/aligocalibration/trunk/Runs/ER8/H1/Measurements/OMCDCPDs/2015-09-02/DCPD_A_1whitening.dat

/aligocalibration/trunk/Runs/ER8/H1/Measurements/OMCDCPDs/2015-09-02/DCPD_B_1whitening.dat

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/Liso/fit_whitening_1st_stage_DCPD_A.fil

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/Liso/fit_whitening_1st_stage_DCPD_B.fil

/aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/python/whitening_1st_stage.py

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/OMCDCPDs/2015-09-02_whitening_1st_stage_DCPD_A.pdf

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/OMCDCPDs/2015-09-02_whitening_1st_stage_DCPD_A.png

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/OMCDCPDs/2015-09-02_whitening_1st_stage_DCPD_B.pdf

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/OMCDCPDs/2015-09-02_whitening_1st_stage_DCPD_B.png

Images attached to this comment
Non-image files attached to this comment
koji.arai@LIGO.ORG - 02:32, Thursday 03 September 2015 (21168)

Are these above-Nyquist-freq poles the ones I've reported with LHO ALOG 17647?
If so, they are the high freq poles associated with the OMC DCPD in-vac preamps.
Since they exist above the Nyquist frequency (~8kHz), it is not straight forward to compensate them.

As they show up like a linear time delay at low freq, we decided to leave them uncompensated in April. (Refer Daniel S, Jeff K).
This corresponds to ~18us delay. I thought this was already accommodated in the DARM calibration model described in LHO ALOG 17951
and the following comments (particularly in LHO ALOG 18037). Were they dropped at some point?

kiwamu.izumi@LIGO.ORG - 07:12, Thursday 03 September 2015 (21171)

Koji,

No. They are not the ones in DCPDC's preamp. These poles are found in the whitening board by directly measuring it.

As for preamp's super-nyquist poles, they have been incorporated in our calibration model and  have been actually used in the upsampled FIR pipeline without approximating it as a time delay. So we did not drop the ones from the preamp.

kiwamu.izumi@LIGO.ORG - 12:16, Thursday 03 September 2015 (21184)

For double chek my conclusion written above, I went back to the original plot in alog 21101. With the newly discovered high frequency poles of the whitening board (alog 21131) included, the measurement agrees with the model with 1-ish % descrepancy up to 5 kHz in magnitude as shown in the attached plot.

This is good enough .

 

The code and figure:

 /aligocalibration/trunk/Runs/ER8/H1/Scripts/OMCDCPDs/Matlab/OMC_DCPD_AnalogChain_TimeSeries.m

/aligocalibration/trunk/Runs/ER8/H1/Results/OMCDCPDs/2015-09-01_OMC_DCPDs_timeseries_analysis.pdf

Non-image files attached to this comment
kiwamu.izumi@LIGO.ORG - 17:09, Thursday 30 June 2016 (28101)

The data for the whitening filters in the above entries are obsolete as of 30/6/2016.

The whitening chassis was replaced by a different unit on June 28th in 2016 (alog 28010). A new measurement was taken on June 30th in 2016 (alog 28087).

H1 SUS
richard.mccarthy@LIGO.ORG - posted 12:50, Tuesday 01 September 2015 - last comment - 17:02, Tuesday 01 September 2015(21095)
SR3 Suspension chain wholesale swap
In an ideal world we would have been able to systematically investigated each stage of the SR3 chain to find where the glitch was coming from.  But with the pressure of needing to get the system up and running I decided to replace all electronics and do a followup in the lab. So this morning we took down the SR3 Front end and installed a new DAC card.  Replace the coil driver SN100186 with SN 100192.  The AI chassis had been replaced last night.  So aside from cabling replacement the SR3 drive chain is new and after 10 minutes we do not see the glitches.  Of course I could go 10 min this morning and not see them.

Also there was a problem with the Voltage Monitor for T2.  This was in the IO chassis ADC interface so we replaced the ADC the ribbon cable and ADC interface card for the SUS Aux chassis.  This fixed problem.  
Comments related to this report
sheila.dwyer@LIGO.ORG - 16:50, Tuesday 01 September 2015 (21111)

This screenshot show the OPlev and witness sensor for SR3 pit.  The problem shows up clearly early monday morning, things got slightly better around 2 am last night for unknown reasons.  This morning after the electronics were swapped, the frames are bad, and now the problem seems to be fixed.  

The second screenshot is a lockloss from last night, in which you can see that before the lockloss, SR3 gets something like 1 urad of pitch in about half a second.  This is visible in both the witness sensor and the oplev although the calibrations don't agree.  We also had smaller glitches that weren't large enough to lock us out of lock, but we think that the large ones were happening about once every 20 minutes or more frequently.  

Images attached to this comment
jenne.driggers@LIGO.ORG - 17:02, Tuesday 01 September 2015 (21114)

Here's a different view of the same thing that Sheila just posted. 

I have 3 1-hour plots of SR3 M3 Wit Pit, all with the same y-axis scale:  (1) Aug 26th at some time when the Cage servo was running, (2) sometime last night, and (3) right now.  The "right now" plot shows the lock aquisition sequence, including the cage servo being engaged, which is why the DC value changes. 

The salient point is that last week, the M3 Wit Pit looked nice and clean.  Last night, even though there weren't huge glitches in the time that I chose, the optic was clearly moving around much more than normal.  Now, the data looks clean again.

Images attached to this comment
H1 ISC
keita.kawabe@LIGO.ORG - posted 12:48, Tuesday 01 September 2015 - last comment - 17:28, Wednesday 02 September 2015(21094)
Harmonic generator testing (Filiberto, Keita)

We pulled both the power supply and the harmonic generator from the remote rack and tested them in the lab, together with spare supply and spare generator. We used a spare 9.1MHz source on the bench.

In the lab, regardless of the combinations (supply and generator), 45MHz thing was clean.

In the rack, we tested the original generator with spare and original supply, with 9.1MHz source coming from the distributor in the rack. In both of the cases there were huge 45+-2MHz-ish humps.

Evan reported in the past that using IFR at the rack didn't change the results, so we didn't bother to look at 9.1MHz source.

In all of these test cases both in the lab and rack, the only thing connected to the harmonic generator was power supply, 9.1MHz source and the network analyzer on 5x output. Everything else was terminated.

We also looked at the supply voltage in the lab. We opened the chassis and used clips to access gnd and +15V test points. Under the load, both of the units didn't show any huge high frequency noise. RMS voltage measured on the scope was about 1mV, which was dominated by some pickup (it got smaller when I hand held the chassis away from the 9.1MHz source). Fil also measured the spectrum and it was within the spec. And anyway, the harmonic generator didn't show any hump in the lab, so the power supply is pretty much exonerated.

Fil put the original units back in.

Comments related to this report
rich.abbott@LIGO.ORG - 13:17, Tuesday 01 September 2015 (21098)ISC
Do the other harmonic harmonic generator output spigots have excess sideband noise?
evan.hall@LIGO.ORG - 14:03, Tuesday 01 September 2015 (21100)

Rich, yes. I took measurements of some of the other ports of the HG in the CER a few days ago (measurements attached).

001.TXT: 45 MHz output

002.TXT: 27 MHz output

004.TXT: 135 MHz output

005.TXT: 90 MHz output

007.TXT: 36 MHz output

Non-image files attached to this comment
rich.abbott@LIGO.ORG - 16:48, Tuesday 01 September 2015 (21113)
There's a clue in the data files you attached.  Looking at the plot of the 45 MHz, you see side lobes at +/- 1MHz.  Looking at the plot of 90 MHz, and 135 MHz you see side lobes with the same offset frequency.  If the source of the pollution was coming into the input of the harmonic generator, then the peaks of the side lobes would scale with frequency.  Given that this is not the case, you are looking for something that effects each frequency directly.  In my opinion, that would most likely point to a power supply issue causing phase modulation of an amplifier common to each output spigot (based on the observation that the induced modulation is about the same in each channel and assuming that's the physical topology of the HG).  

There is 50dB of separation between the peak of the carriers and the side lobes, so you can produce a spectrum like that with a pretty small 1 MHz noise hump on a power supply rail.  I would be wanting to look at the HG power supply directly with an RF spectrum analyzer (be sure to AC couple the power supply to the spectrum analyzer or else you will need to buy a new spectrum analyzer, 1000pF would suffice)

I don't know exactly how you are measuring these noise peaks, but I guess it could also be something in the particular spectrum analyzer (if you are using a different analyzer in the shop for example).  Have you looked at a "clean" signal to be sure you don't see it on all observed signals with that particular analyzer?  Sorry if this is simplistic, you may well have already vetted this and wrote about it only to have me forget somewhere.

I now wish I had popped the top on the HG and its power supply.  I have been itching to do that for a while, but missed the opportunity while I was there this weekend.  I'd be super interested to see a photo of the insides if anyone felt like looking...
daniel.sigg@LIGO.ORG - 00:28, Wednesday 02 September 2015 (21129)

The power supply is a LIGO low noise unit boxed into a standard chassis. More details here. Possible points of investigations: power cable shielding, power decoupling at the generator side, grounding issues.

evan.hall@LIGO.ORG - 05:21, Wednesday 02 September 2015 (21132)

I went back and looked at the IFR data from a few days ago, and it seems that this may be a problem with the 9 MHz coming from the OCXO. The first attachment shows the output of the harmonic generator when powered from the IFR versus the OCXO. The IFR measurement still has peaks around the 45 MHz, but they are much smaller than with the OCXO.

As a check, Dan and I measured the spectrum directly out of the IFR and out of the OCXO (no distribution amplifier involved). In both cases, the spectrum on either side of 9.1 MHz looks pretty clean, but the OCXO has much worse noise between 0 and 2 MHz, and the shape qualitatively matches the peaks that are seen on the outputs of the harmonic generator.

We also did some related tests, like looking at the 45 MHz spectrum of the spare HG when powered from the 9 MHz distribution amplifier. This spectrum has the same huge peaks as the primary HG.

Keita and I looked at the noise from the ±15 V power supply, but we didn't see anything outrageous. As advised, we ac coupled the spectrum analyzer with 1 nF. The spectrum seemed to be roughly a few hundred nV/Hz1/2 out to a few megahertz, but we found it hard to get a clean measurement.

Non-image files attached to this comment
rich.abbott@LIGO.ORG - 10:52, Wednesday 02 September 2015 (21137)
I misspoke.  The offset frequency of PM or FM sidebands in a multiplied spectrum remains constant, but the sideband power scales with the multiplication factor.  

9.1MHz carrier (W) with sinusoidal sideband (Wm) before multiplication:
COS[W*t + A*SIN(Wm*t)]

Derivative of argument for angular Frequency:
W + A*Wm*COS(Wm*t)

After frequency multiplication of factor N:
N*W + N*A*Wm*COS(Wm*t)

Sideband frequency unchanged, power scaled by N

That being said, the sideband power is not scaling by N in the data I saw posted.  The carrier could still be amplitude modulated, but I don't see how it could be phase or frequency modulated.  Sorry for my earlier flawed theory on frequency multiplication.

If someone would please figure this out, I could do a much better job of warping theory to fit observation.

Conclusion:  There might be AM being induced on either on the 9.1MHz carrier, or somewhere inside the harmonic generator - for what little that does to help.

daniel.sigg@LIGO.ORG - 12:51, Wednesday 02 September 2015 (21144)

The direct RF spectrum of the 9.1MHz shows no side lopes at 1-2MHz offset. This describes the total power including both AM and FM sidebands. Odd harmonics generators are typically squaring up the fundamental and then filter out the desired frequency. So, they should be first order insensitive to AM.

rich.abbott@LIGO.ORG - 17:28, Wednesday 02 September 2015 (21159)
You are right about the limiting Daniel.  Evan saw sidebands on the OCXO input too.  I attach a plot of the 45.5, 91, and 135 MHz spectra frequency shifted for relative comparison (Data taken from earlier post).
Non-image files attached to this comment
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