 Wed Aug 3 02:28:08 2011, Manuel, Ishwita, Update, WienerFiltering, Wiener Filtering in X-arm 
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| Wiener Filtering was applied on the data collected from the X-arm during the time: GPS time-996380715 (Aug 02, 2011. 21:25:00. PDT) to GPS time-996382215 (Aug 02, 2011. 21:50:00. PDT) for a duration of 1500 seconds. During this time the X-arm was locked, we checked it by acquiring |
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Wed Aug 3 12:24:08 2011, Manuel, Ishwita, Update, WienerFiltering, Weekly summary
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Last Friday (Jul 29) we reinstalled the blue breakout box, and changed the names of the C1:PEM channels. Elog
Reference
We continued the work on the simulation ad applied wiener filter on the simulated ground motion, but the result is unsatisfactory, yet. We will |
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Tue Aug 9 16:21:59 2011, Manuel, Ishwita, Update, WienerFiltering, First results of our simulations
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We did the simulation of the stacks by defining a transfer function for one stack (green plot) and another
similar transfer function for the other stack.
We simulated the ground motion by filtering a white noise with a low pass filter with a cutoff frequency at 10Hz. ( |
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Fri Nov 25 12:46:13 2011, Mirko, Update, WienerFiltering, Wiener filtering tryout
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Tried the wiener filter with the TF from p.5900
Tried it out with the TFs from p.5900:
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Mon Nov 28 18:53:35 2011, Den, Summary, WienerFiltering, seismic noise substraction 9x
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There is still a problem why GUR, STS signals are poorly coherent to MC_L. But at least we can see coherence at 2-5 Hz. It might be useful to do
something with adaptive filtering because it does not work at all for a long time. We start with Wiener filtering. I still doubt that static filtering
is useful. Adaptive filter output is linear to its coefficients, so why not to provide adaptive filter with a zero approximation equal to calculated Wiener |
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Tue Dec 6 00:58:34 2011, Den, Update, WienerFiltering, OAF current goal
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After reducing the digital noise I did offline Wiener filtering to see how good should be online filter. I looked at the MC_F and GUR1_X and GUR1_Y signals.
Here are the results of the filtering. The coherence is plotted for MC_F and GUR1_X signals.
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Wed Aug 15 00:52:17 2012, Den, Update, WienerFiltering, filter calculation
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A Matlab script to calculate Wiener filter coefficients and convert fir to iir is ready. Input is a file with zero mean witness and desired signals,
output is a Foton zpk command to specify iir filter.
The plot shows comparison of offline fir , iir and online iir filtering. Spectrum below 4 Hz is still oscillating due to acoustic coupling, this |
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Thu Nov 1 20:20:33 2012, Den, Ayaka, Update, WienerFiltering, acoustic noise in PMC
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We've subtracted acoustic noise from PMC using 1 EM 172 microphone. We applied a 10 Hz high-pass filter to PMC length signal and 100,200,300:30,30 to
whiten the signal.We used ~10 minutes of data at 2048 Hz as we did not see much coherence at higher frequencies.
We were able to subtract acoustic noise from PMC length in the frequency range 10-700 Hz. In the range 30-50 Hz error signal is less by a factor |
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Mon Nov 5 20:37:01 2012, Ayaka, Update, WienerFiltering, Play with wiener filtering
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I am trying to find what limits the reduction rate with wiener filtering.
I did some calculations below:
Reduction rate estimation by microphone noise |
 Thu Nov 8 10:11:58 2012, Ayaka, Update, WienerFiltering, Play with wiener filtering
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I will attach a document which describes how the noise affect the wiener filter and the noise cancellation ratio.
And I re-estimate the SN ratio in the microphone (but still rough):
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Tue Nov 13 21:05:22 2012, Ayaka, Update, WienerFiltering, Acoustic noise cancellation with MC 9x
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In order to perform acoustic noise cancellation with MCL signal, I am trying to find sweet spots for microphones.
I set microphones at various places around MC chambers, and see how coherent microphones and MC signals are.
I had checked the half part of MC. |
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Tue Nov 27 01:03:42 2012, Ayaka, Update, WienerFiltering, Sound on PSL
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Last Thursday, I put the speaker and my laptop in the PSL table, and make triangular wave sound with the basic frequency of 40Hz, and Gaussian
distributed sound.
(I create the sounds from my laptop using the software 'NHC Tone Generator' because I could not find the connector from BNC to speaker plug.) |
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Wed Nov 28 23:55:13 2012, Ayaka, Update, WienerFiltering, Sound on PSL
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I have been searching for the way we can subtract signal better since I could see the acoustic coupling signal remains in the target signal even
though there are no coherence between them.
I changed the training time which is used to decide wiener filter. |
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Wed Dec 5 01:06:22 2012, Ayaka, Update, WienerFiltering, The microphones and the speaker on the AP table
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In order to see the acoustic coupling on arm signals, I set 6 microphones and the speaker on the AP table. The microphones are not seismically
isolated for now.
I have a signal generator under the AP table. |
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Wed Dec 5 09:53:01 2012, rana, Update, WienerFiltering, The microphones and the speaker on the AP table
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| Don't try to re-invent the mic mount: just copy the LIGO mic mount for the first version. |
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Thu Dec 13 18:06:59 2012, Ayaka, Update, WienerFiltering, New microphone mounts
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Yesterday, I made new mounts for microphones.
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Mon May 13 17:24:38 2013, Jenne, Update, WienerFiltering, PRM YAW Wiener filtering
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I have done a quicky offline Wiener filter to check how much PRM yaw motion we can subtract using a seismometer in the corner station. This work
may be redundant since Koji got the POP beam shadow sensor feedback loop working on Friday night.
Anyhow, for now, I used the GUR2 channels, since GUR2 was underneath the ITMX chamber (at the north edge of the POX table). Note that Zach |
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Thu Aug 6 21:03:45 2015, Ignacio, HowTo, WienerFiltering, How to do online static IIR Wiener filtering
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In order to do online static IIR Wiener filtering one needs to do the following,
1) Get data for FIR Wiener filter witnesses and target.
2) Measure the transfer function (needs to be highly coherent, ~ 0.95 for all points) from the actuactor to the control signal of interest |
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Tue Sep 1 06:58:11 2015, Ignacio, Update, WienerFiltering, MCL FF => WFS1 and WFS2 FF => ARMS FF 6x
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I took some training data during Sunday night/Monday morning while the MCL MISO FF was turned on. We wanted to see how
much residual noise was left in the WFS1/WFS2 YAW and PITCH signals.
The offline subtractions that can be achieved are: |
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Mon Dec 14 16:46:42 2015, ericq, Update, WienerFiltering, Noise Subtraction Puzzler
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Here's something to ponder.
Our online MCL feedforward uses perpendicular vertex T240 seismometer signals as input. When designing a feedforward filter, whether FIR Wiener
or otherwise, we posit that the PSD of the best linear subtraction one can theoretically achieve is given by the coherence, via Psub = P(1-C). |
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Thu Jan 7 15:29:54 2016, ericq, Update, WienerFiltering, Noise Subtraction Puzzler
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The puzzle continues...
I found some reference for computing "multicoherence," which should properly estimate the potential MISO subtraction potential in situations
where the witness channels themselves have nontrivial coherence. Specifically, I followed the derivations in LIGO-P990002. |
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Thu Jan 14 15:08:37 2016, ericq, Update, WienerFiltering, Noise Subtraction Puzzler
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The anticlimatic resolution to my subtraction confusion: Spectral leakage around 1Hz. Increasing the FFT length to 256 sec now shows that the FIR
WF pretty much achieves the ideal subtraction.
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Thu Jan 14 18:41:36 2016, rana, Update, WienerFiltering, Noise Subtraction Puzzler
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Just not just pedagogical ! Freq domain MISO coherence based subtraction estimation is much faster than calculating MISO WF. And since each bin
is independent of each other, this gives us an estimate of how low the noise can go, whereas the Wiener filter is limited by Kramers-Kronig. We should
be able to use this on the L1 DARM channel to do the noise hunting as well as estimating the subtraction efficacy of the pseudo channels that you and Rory |
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Fri Apr 1 13:11:26 2016, ericq, Update, WienerFiltering, Bilinear Noise Testing
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I've been banging my head against bilinear noise subtraction, and figured I needed to test things on some real hardware to see if what I'm doing
makes sense.
I ran the ASS dither alignment on the Y arm, which ensures that the beam spots are centered on both mirrors. |
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Tue Jun 10 11:54:36 2014, Zach, Configuration, Wiki, DokuWikis are still down
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Not sure if someone is already on this, but the nodus DokuWikis are still down (AIC, ATF, Cryo, etc.)
I get:
DokuWiki Setup Error
The |
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Tue Jun 10 19:11:27 2014, Evan, Configuration, Wiki, DokuWikis are back up
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As of this writing, the DokuWiki appears to be
working.
As you and I suspected, it looks like this was a clusterwhoops with the permissions for the NFS mount. Let's recap what happened in the past 24 |
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Wed Jun 11 05:16:14 2014, Zach, Configuration, Wiki, DokuWikis are back up
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It looks like auth is broken on the AIC wiki (though working fine on ATF and Cryo). I did some poking around
but can't see how anything we did could have broken it.
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Wed Jun 11 10:15:15 2014, Evan, Configuration, Wiki, DokuWikis are back up
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Quote:
It looks like auth is broken on the AIC wiki (though working fine on ATF and Cryo). I did some poking |
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Wed Jun 11 20:09:37 2014, Zach, Configuration, Wiki, DokuWiki situation
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I have been looking into the DokuWiki situation, with no great progress so far.
The problem is with authentication. When you try to access the wiki, you get: "User authentication is temporarily unavailable. If this situation persists, please inform your Wiki |
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Fri Aug 8 16:45:40 2014, Nichin, Update, Wiki, PDFR wiki updated
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The PDFR system has been documented in the 40m wiki and all the relevant information about making changes and keeping it updated have been mentioned.
https://wiki-40m.ligo.caltech.edu/Electronics/PDFR_system
This pretty much wraps up my SURF 2014 project at the 40m lab. |
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Mon Aug 11 23:50:38 2014, rana, Configuration, Wiki, DokuWikis are back up
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Quote:
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Thu Aug 14 20:52:36 2014, rana, Update, Wiki, Violin Mode table added to Wiki
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Mech Resonance Wiki
I've updated the wiki by trawling the elog for violin entries. Please keep it up to date so that we can make violin notches.
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Mon Apr 10 15:22:46 2017, rana, Configuration, Wiki, DokuWikis are back up
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| AIC Wiki updated to latest stable version of DokuWiki: 2017-02-19b "Frusterick Manners" + CAPTCHA + Upgrade + Gallery PlugIns |
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Thu Apr 19 09:57:03 2018, gautam, Update, Wiki, AP and ETMX tables uploaded to wiki
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The most up to date pictures of the AP table and ETMX table that Steve took have been uploaded to the relevant
page on the wiki. It seems like the wiki doesn't display previews of jpg images - by using png, I was able to get the thumbnail of the attachment
to show up. It would be nice to add beam paths to these two images. The older versions of these photos were moved to the archive section on the same page. |
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Fri Apr 20 16:25:08 2018, Steve, Update, Wiki, ETMX table layout uploaded to wiki
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| ETMX table layout uploaded with beam paths to the wiki. |
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Tue Apr 24 15:59:23 2018, Steve, Update, Wiki, AP table layout 20180328
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Quote:
ETMX table layout uploaded with beam paths to the wiki.
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Tue Aug 21 09:16:23 2018, Steve, Update, Wiki, AP table layout 20180821
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Wed Jun 24 22:47:21 2020, Yehonathan, Update, Wiki, Updated phase maps webpage
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I uploaded the new phase maps measurements made by GariLynn to nodus and updated the optics phase maps page.
I
also added MetroPro and Matlab analysis for these phase maps. |
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Tue Oct 6 07:37:20 2020, yehonathan, Update, Wiki, New TIS measurements of 40m Optics
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LiYuan has kindly done some Total Integrating Sphere (TIS) measurements on ITMU01 and ITMU02. A summary of the measurement is attached. I uploaded the
measurements and some analysis script to nodus at /home/export/home/40m_TIS. I created a Wiki
page for the measurements and linked to it from the core optics page. |
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Mon Jan 24 12:33:41 2022, rana, Configuration, Wiki, AIC Wiki: txz files allowed
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I updated the mime.local.conf file for the AIC Wiki so as to allow attachments with the .txz
format. THis should be persistent over upgrades, since its a local file. |
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Sun Dec 21 13:00:06 2008, steve, Update, all down cond., vac and laser back on
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There was a power outage sometimes early Saturday.
All things are down.
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Tue Sep 29 23:43:49 2009, rana, AoG, all down cond., Cosmic
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cosmic rays in cars |
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Sun Nov 29 16:56:56 2009, rob, AoG, all down cond., sea of red
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Came in, found all front-ends down.
Keyed a bunch of crates, no luck: |
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Mon Nov 30 10:28:47 2009, Alberto, AoG, all down cond., sea of red
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Quote:
Came in, found all front-ends down. |
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Mon Nov 30 11:29:40 2009, Alberto, AoG, all down cond., sea of red
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Quote:
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Sat Dec 5 14:41:07 2009, rob, AoG, all down cond., sea of red, again
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Taking a cue from entry 2346, I immediately went for the nuclear
option and powered off fb40m. Someone will probably need to restart the backup script. |
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Sat Dec 5 15:20:10 2009, Jenne, AoG, all down cond., sea of red, again
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Quote:
Taking a cue from entry 2346, I immediately went for |
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Sun Dec 5 22:28:39 2010, rana, Summary, all down cond., power outage
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Looks like there was a power outage. The control room workstations were all off (except for op440m). Rosalba and the projector's
computer came back, but rossa and allegra are not lighting up their monitors.
linux1 and nodus and fb all appear to be on and answering their pings. |
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Mon Dec 6 11:53:20 2010, josephb, kiwamu, Summary, all down cond., power outage
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The monitors for allegra and rossa's seemed to be in a weird state after the power outage. I turned allegra and rossa on, but didn't see anything.
However, I was after awhile able to ssh in. Power cycling the monitors did apparently got them talking with the computers again and displaying.
I had to power cycle the c1sus and c1iscex machines (they probably booted faster than linux1 and the fb machines, and thus didn't see their root |
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Mon Dec 6 11:57:21 2010, Koji, Summary, all down cond., power outage
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I checked the vacuum system and judged there is no apparent issue.
The chambers and annulus had been vented before the power failure.
So the matters are only on the TMPs. |