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ID Date Authorup Type Category Subject
  1715   Thu Jul 2 16:45:06 2009 ClaraUpdatePEMBonnie and Clyde are officially in operation! (Butch Cassidy and the Sundance Kid are in temp position)

I hooked up Bonnie and Clyde last night and tested it today. First I tried some loud noises to make sure I could identify them on the readout. Then, Steve suggested I try to look for some periodic stuff. I set up Butch Cassidy and the Sundance Kid on the cabinets by the MC2 optic. Now for graphs!

 

bonnie_test_marked.png

I tapped on the microphone a few times. I also yelled a bit, but this is sampling by seconds, so perhaps they got overwhelmed by the tapping.

bonnie_test2_marked.png

This time I tried some more isolated yells. I started with a tap so I'd be sure to be able to recognize what happened. Apparently, not so necessary.

bonniebutch_2sbeat_marked.png

Here, it looks like a pretty strong periodic pattern on the second mic (Butch Cassidy). I replaced the lines with dashed ones where the pattern was a little less clear. Possibility interference from something. Mic1 (Bonnie) seems to show a pretty regular beat pattern, which seems reasonable, as it isn't particularly close to any one instrument fan.

 

So, anyway. I thought those were neat. And that I wanted to share.

 

  1718   Tue Jul 7 16:06:59 2009 ClaraUpdateComputer Scripts / ProgramsDTT synchronization errors, help would be appreciated

I am attempting to use the DTT program to look at the coherence of the individual accelerometer signals with the MC_L signal. Rana suggested that I might break up the XYZ configuration, so i wanted to see how the coherence changed when I moved things around over the past couple of weeks, but I keep getting a synchronization error every time I try to set the start time to more than about 3 days ago. I tried restarting the program and checking the "reconnect" option in the "Input" tab, neither of which made any kind of difference. I can access this data with no problem from the Data Viewer and the Matlab scripts, so I'm not really sure what is happening. Help?

EDIT: Problem solved - Full data was not stored for the time I needed to access it for DTT.

  1723   Wed Jul 8 12:36:15 2009 ClaraUpdatePEMCoherences and things

After setting up the microphones last week, I modified the Wiener filtering programs so as to include the microphone signals. They didn't seem to do much of anything to reduce the MC_L signal, so I looked at coherences. The microphones don't seem to have much coherence with the MC_L signal at all. I tried moving Bonnie to near the optical table next to the PSL (which isn't in a vacuum, and thus would, presumably, be more affected by acoustic noise), but that didn't seem to make much of a difference. Eventually, I'd like to put a mic in the PSL itself, but I need to work out how to mount it first.

DSC_0564.JPG

Bonnie's new location.

You can see in bonnie_butch.pdf that none of the mic signals are giving very good coherence, although they all seem to have a peak at 24 Hz. (In fact, everything seems to have a peak there. Must be a resonant frequency of something in the mode cleaner.)

I've also attached plots of the coherences for all six accelerometers and the three Guralp seismometer axes. I plotted the most coherent traces together in the last pdf: the y-axes of the MC2 accelerometer and the two seismometers (the Ranger measures ONLY y) and, interestingly, the z-axis of the MC2 accelerometer. Unsurprisingly, the seismometers are most coherent at the low frequencies, and the MC2-Y accelerometer seems to be coherent at very similar frequencies. The MC2-Z accelerometer, on the other hand, seems to be coherent at the higher frequencies, and is highly complementary to the others. I am not really sure why this would be...

Finally, I was curious about how the noise varies throughout the day, because I didn't want to mistakenly decide that some particular configuration of accelerometers/seismometers/whatever was better than another b/c I picked the wrong time of day to collect the data. So, here is a plot of Wiener filters (using only accelerometer data) taken over 2-hour intervals throughout the entirety of July 6, 2009 (midnight-midnight local).

2hr_allday_1.png

It's a little bit confusing, and I should probably try to select some representative curves and eliminate the rest to simplify things, but I don't have time to do that before the meeting, so this will have to suffice for now.

Attachment 2: bonnie_butch.pdf
bonnie_butch.pdf
Attachment 3: Gseis_100.pdf
Gseis_100.pdf
Attachment 4: mc1_xyz.pdf
mc1_xyz.pdf
Attachment 5: mc2_xyz.pdf
mc2_xyz.pdf
Attachment 6: most_coherent.pdf
most_coherent.pdf
  1726   Wed Jul 8 19:42:37 2009 ClaraUpdatePEMBonnie moved to PSL, getting some coherence with the PMC_ERR channel

In her position overlooking whichever table it is that is next to the PSL, Bonnie drummed up some decent coherence with the PSL-PMC_ERR channel, but not so much with the MC_L. I moved her into the PSL itself, and now there is rather good coherence with the PMC_ERR channel, but still not so great for MC_L.

DSC_0567.JPG

Bonnie's new home in the PSL.

Attachment 2: bonnie2_pmcerr.pdf
bonnie2_pmcerr.pdf
Attachment 3: bonnie_PSL.pdf
bonnie_PSL.pdf
  1728   Thu Jul 9 19:05:32 2009 ClaraUpdatePEMmore mic position changes; mics not picking up high frequencies

Bonnie has been strung up on bungees in the PSL so that her position/orientation can be adjusted however we like. She is now hanging pretty low over the table, rather than being attached to the hanging equipment shelf thing. Butch Cassidy has been hung over the AS table.

Moving Bonnie increased the coherence for the PMC_ERR_F signal, but not the MC_L. Butch Cassidy doesn't have much coherence with either.

I noticed that the coherence would drop off very sharply just after 10 kHz - there would be no further spikes or anything of the sort. I used my computer to play a swept sine wave (sweeping from 20Hz to 10kHz) next to Butch Cassidy to see if the same drop-off occurred in the microphone signal itself. Sure enough, the power spectrum showed a sharp drop around 10kHz. Thinking that the issue was that the voltage dividers had too high impedance, I remade one of them with two 280 Ohm and one 10 Ohm resistor, but that didn't make any difference. So, I'm not sure what's happening exactly. I didn't redo the other voltage divider, so Bonnie is currently not operating.

 

Attachment 1: DSC_0569.JPG
DSC_0569.JPG
Attachment 2: DSC_0570.JPG
DSC_0570.JPG
Attachment 3: bonnie_psl_hi_mcl12.pdf
bonnie_psl_hi_mcl12.pdf
Attachment 4: bonnie_psl_hi_errf12.pdf
bonnie_psl_hi_errf12.pdf
Attachment 5: bc_as_table.pdf
bc_as_table.pdf
Attachment 6: powerspec.pdf
powerspec.pdf
  1744   Tue Jul 14 16:31:46 2009 ClaraUpdatePEMFrequency Response of Microphone (Bonnie)

So, I actually took these measurements last week, but I didn't get around to making nice plots and things until now. I figured the time while I wait for the spectrum analyzer to do its thing was a good time.

Having been unable to locate the SR785 and also unsure how to connect it to a computer speaker (and also unable to find a free one), I downloaded a demo of a function generator onto my computer and just used that. (Same thing I used to do the swept sine that created the frequency power response plots I posted last week.) I set the program to a number of different frequencies and had the other end of the cable hooked into the oscilloscope to see a) if I could pick out the frequency and b) see how the magnitude of the microphone output varied with the frequency.

The first set of measurements I took, I didn't realize that I could increase the output power of the function generator. Because the generated sound at the default setting was relatively quiet, the oscilloscope traces were pretty chaotic, so I usually froze the trace so that I could look at it better. I ended up with a lot of weird jumps in the magnitude, but I later realized that there was a lot of beating going on at some frequencies, and the amplitude changes were probably much more drastic for the -20 dB sounds than the 6 dB sounds, since it was closer in amplitude to the surrounding noises. So, I've included that data set in my plots for the sake of completeness, but I'm pretty sure that it is useless.

Once I realized I could increase the power output for the signal generator, I took a set of data with and without the voltage divider at 6 dB. There was a cluster of frequencies that showed significant beating around 1700-3000 Hz in the data WITH the voltage divider, but I did not see any clear beating in the data WITHOUT. In the plots, I simply plotted up the highest and lowest amplitudes I measured for the frequencies with significant beating, since it was obviously hard to tell what the amplitude would have been without any background noise. In the w/o volt. div. set, although I didn't see any obvious beat patterns, the measured amplitudes did jump slightly at the frequencies that showed beats with the voltage divider. So, perhaps I was just not seeing them, but they influenced my amplitude measurements? I'm not sure if it would be possible for the voltage divider itself to cause beat frequencies.

 (Note: the amplitudes measured were from zero to peak, as the oscilloscope I was using wouldn't show a big enough vertical range to easily measure the peak-to-peak voltage difference.)

I've attached two plots of my measurements. One has a regular x-scale and includes all the measurements. The second has a logarithmic x-scale and omits the 20 Hz points. I had some troubles being able to pick out the 20 Hz signal on the oscilloscope... I don't know if my computer speakers just don't work well at that frequency or what, but either way, those points seemed highly suspect, and omitting them from the log plot allowed me to spread things out more.

One thing I'm not sure about is the 3000 Hz point. It was one of the ones with a beat frequency (~130 Hz), and the amplitudes were pretty low. The corresponding point from the non-voltage-divider data set is also low. So, I'm not sure what's happening there.

The one thing that I do think is quite clear is that the 1000 Hz drop-off in power when the microphone is connected to the ADC has nothing to do with the voltage divider. Beat issues aside, the shapes are very similar (pay no attention to the absolute scale... obviously, the voltage responses with and without the voltage divider were very different, and I just scaled them to fit in the same plot).

Update: Jenne pointed out that I was not absolutely clear about the voltage scale in my plots. The GREEN and BLUE points are on a mV scale, and the RED points are on a 10mV scale. I should probably redo the plots in Matlab in eventuality, since Excel is hard to use if you want to do anything that is not extremely basic with your plots, but this was my solution for the time being. So, the fact that the RED points, which are the data taken WITHOUT the voltage divider, are lower than the GREEN ones does not in any way indicate that I measured lower voltages when the voltage divider was not used.

Also, a to do list:

- Many of the beat frequencies I picked out were veeeeery slow, indicating that something is going at a frequency that is very close to the arbitrary frequencies I chose to sample, which is a little strange. That, combined with the fact that I saw clear beats with the voltage divider but not without leads me to believe that it may be worth investigating the frequency response of the voltage divider itself.

- Redo the measurements near the anomalous 3000 Hz point with a higher density of sampled frequencies to try to see what the heck is going on there.

Attachment 1: Bonnie_fres_regplot.pdf
Bonnie_fres_regplot.pdf
Attachment 2: Bonnie_fres_logplot.pdf
Bonnie_fres_logplot.pdf
  1757   Thu Jul 16 10:52:58 2009 ClaraUpdatePEMSingle Channel TRS-RNC Cable

I made and tested a female-to-female TRS(audio)-RNC cable. It only has a single channel, so it won't work for stereo speakers or anything, but I should only need one speaker for testing the microphones. The tip of the plug is the signal, the sleeve is ground, and the ring is null.

  1760   Fri Jul 17 18:04:54 2009 ClaraUpdatePEMGuralp Box Fail

I've been trying for most of the week to get noise measurements on the output of the Guralp box as well as scross the AD640 chip. The measurements haven't really been making sense, and, being at a loss as to what else I should try, I decided to redo the resistors on the N/S 2 and E/W 2 channels. (I had been comparing the VERT1 and VERT2 channels, as VERT1 has been restuffed and VERT2 has not.) I don't need all three of the second set of channels to do more measurements, so it seemed like a good use of time.

The first thing I noticed was that the VERT2 channel was missing two resistors (R24 and R25). I probably should have noticed this sooner, as they are right by the output points I had been measuring across, but it didn't occur to me that anyone did anything to the VERT2 channel at all. So, probably the measurements on VERT2 are no good.

VERT2_missing_resistors.png

Note the existence of 100 kOhm resistors on the top channel, and none on the bottom channel (VERT2).

 

Then, while I was soldering in some 100 Ohm resistors, I happened to notice that the resistors I was using had a different number (1001) on them than the corresponding ones on the already redone channels (1003). I checked the resistance, and the ones on the already redone channels turned out to be 100 kOhm resistors, rather than 100 Ohms. So, I double checked the circuit diagram to make sure that I had read it correctly, and there were a number of resistors that had been relabeled as 100 Ohms and several relabeled as 100 kOhms. On the board, however, they were ALL 100 kOhms. Clearly, one of them is wrong, and I suspect that it is the circuitboard, but I don't know for sure.

resistors_diagram.png

resistors_board.png

The diagram clearly shows that R6 should be a 100k resistor, while R5 and R8 should be 100 Ohm resistors, but they are all the same (100k) on the board. I suspect this may have something to do with larger-than-expected noise measurements. But, it's possible the diagram is wrong, not the board. In any case, I didn't really know what to do, since I wasn't sure which was right, so I just replaced all the resistors I was sure about and removed the 100k and 100 Ohm resistors without replacing them with anything. Incidentally, the box of 100kOhm resistors seems to be missing, so I wouldn't have been able to finish those anyway.

  1767   Tue Jul 21 13:55:08 2009 ClaraUpdatePEMGuralp Box Success!

There managed to be just enough 100 kOhm resistors to stuff all the "2" channels (VERT2, N/S2, E/W2) with the fancy low-noise resistors. The first six channels (VERT 1/2, NS 1/2, EW 1/2) are now completely done with the thin-film resistors, taking into account the changes that were made on the circuit diagram. I also replaced the C8 capacitor with the fancy Garrett ones and added capacitors on top of R4 and R13 (after painstakingly making sure that the capacitances are exactly the same for each pair) for the "2" channels. It looks like the capacitors on the "1" channels are the cheaper ones. I will compare the noise measurements later to see if there is any difference - if so, I can replace those as well (although, we're out of the 1 uF capacitors needed for C8).

Speaking of, we are now out of or very low on several types of the Garrett resistors/capacitors: 1 uF, 1kOhm, 100 Ohm, 14.0 Ohm, and 100 kOhm. I left the specifics on Steve's desk so that more can be ordered for the eventual time when the third set of channels needs to be restuffed.

  1800   Tue Jul 28 16:03:14 2009 ClaraUpdatePEMGuralp Seismometer cable pin diagram

I mapped out the corresponding pins on both ends of the Guralp seismometer cable. Here is the diagram:

guralp_pin_diagram.png

The circular 26-pin end of the cable (that plugs into the seismometer) is labeled as above. The other end (the 39-pin end) is not physically numbered, so I just came up with a numbering system. They are both pictured on the non-cable end of the connector. The colored circles indicate the pin pairs.

 

FROM JENNE, 30JULY2009:  the Dsub end is 37 pin, not 39.

  1806   Wed Jul 29 13:15:35 2009 ClaraUpdatePEMDents = Bad??

I was in the lab last night accelerometerizing and noticed some dents on the tubes that stick out horizontally from the MC2 optical chamber (sorry, I don't know what they're called or what they do). One of them is pretty big... I don't know if this is a problem, but it probably isn't a good thing. Photos below:

big_dent1.png

big_dent2.png

small_dent.png

This last one is a little hard to see... I was having trouble getting a good angle on it, but it's there. Not quite as significant as the first one though. (The first two pictures are of the same dent.)

  1859   Fri Aug 7 16:53:35 2009 ClaraUpdatePEMGuralp breakout box noise, finally

After many issues, I finally have some Guralp box noise. I did not measure every single channel with high resolution at the low frequencies because that would have taken about 3 years, but I could perhaps take some faster measurements for all of them if necessary.

output_vallwr2_ns3_1.png

tp3gnd_vallwr2_ns3.png

  1885   Tue Aug 11 02:15:20 2009 ClaraUpdatePEMGuralp breakout box circuit diagram

While writing my progress report, I redrew the Guralp breakout box circuit diagram with all the changes marked. Since only one hard copy exists, I thought it might be useful to post my drawing up in case it is needed for any reason. The two drawings are the same - the second has just been broken into two parts to make it easier to fit on a normal 8.5 x 11 or A4 sheet of paper. The gains for each opamp have not been marked, but they could very easily be added in if necessary. The black resistances and capacitances are the originals. All changes have been indicated in blue.

Guralp_circuit_whole.png

Guralp_circuit_broken.png

  1900   Fri Aug 14 02:57:46 2009 ClaraUpdatePEMRedo of the Huddle Test

I put all three seismometers and all six accelerometers together in the foam box with peanuts. Three of the accelerometers are facing in the x-direction and three are in the y-direction. Both Guralps are aligned on the NS axis and the Ranger is pointing vertically.

**EDIT: The accelerometers are in the x and z directions, not x and y. Sorry, I was sleepy when I wrote this.**

One of the accelerometers was refusing to show anything, and after a few hours of checking connections and swapping cables, I discovered that someone had unplugged the cable from the ADC. A quick glance in the dataviewer shows that the channel has been unplugged since about 3 in the afternoon on August 8th (Saturday). So... obviously all the accelerometer measurements made with that channel since then did not actually get recorded. Yay.

Anyway, as of 2:45, everything is working and taking data. Clearly we're not getting a full night's worth... hopefully that's okay.

  1907   Fri Aug 14 18:33:02 2009 ClaraUpdate Record of Accelerometer and Seismometer Movements

Rather than make a new elog post every time I move something, I'm going to just keep updating this Google spreadsheet, which ought to republish every time I change it. It's already got everything I've done for the past week-ish. The spreadsheet can be accessed here, as a website, or here, as a pdf. I will still post something nightly so that you don't have to search for this post, but I wanted to be able to provide more-or-less real-time information on where things are without carpet-bombing the elog.

  1911   Sat Aug 15 18:35:14 2009 ClaraFrogsComputersHow far back is complete data really saved? (or, is the cake a lie?)

I was told that, as of last weekend, we now have the capability to save full data for a month, whereas before it was something like 3 days. However, my attempts to get the data from the accidentally-shorted EW2 channel in the Guralp box have all been epic failures. My other data is okay, despite my not saving it for several days after it was recorded. So, my question is, how long can the data actually be saved, and when did the saving capability change?

  1913   Sat Aug 15 22:50:18 2009 ClaraUpdateLockingMode Cleaner is out of lock again

It was fine when I came in earlier today, but I just got back from dinner, and it's not good. I looked in dataviewer, and it seems to have been sliding out for the past couple of hours... Here is a picture:

MC_trans.png

I swear I am not responsible this time... all I've been doing is working in the control room.

  1914   Sun Aug 16 04:33:11 2009 ClaraUpdateLockingMode Cleaner is out of lock again

Quote:

It was fine when I came in earlier today, but I just got back from dinner, and it's not good. I looked in dataviewer, and it seems to have been sliding out for the past couple of hours... Here is a picture:

MC_trans.png

I swear I am not responsible this time... all I've been doing is working in the control room.

 Mode cleaner bounced back on its own about 2 hours ago.

  1918   Mon Aug 17 07:01:09 2009 ClaraUpdatePEMADC noiseness

I shorted the inputs on three channels and the outputs on three channels of the Guralp box, and I did similar things with the accelerometers. I was going to move the instruments themselves back, but I didn't have time, so they are still in the box in the corner. If the setup could stay as-is for at least a few hours, that would be awesome.

  1866   Fri Aug 7 20:43:35 2009 Clara, Jenne, Rana, JanUpdatePEMTwo Guralps plugged in, prepped for huddle test

Both Guralps and the Ranger have been placed in our nice new insulated foam box, complete with packing peanuts, in the corner between the x and y arms. The Guralp breakout box has been reinstalled and everything is plugged in in prepartion for the huddle test. However, we're having some issues with ADC channels, which will be worked out tomorrow (hopefully) so that data can be collected over the weekend.

Currently, one Guralp is plugged into the three SEIS-MC1 channels. We made new channels for the second Guralp (GUR-EW, GUR-NS, and GUR-VERT), but had issues with those. So, EW and NS have been plugged into PEM_AUDIO-MIC1 and MIC2 for the time being.

Attachment 1: Untitled.png
Untitled.png
  12750   Tue Jan 24 17:52:15 2017 CraigUpdateOptical LeversETMY Oplev HeNe is replaced

Steve, Craig, Gautam

Today Steve replaced the ETMY He/Ne sr P919645 OpLev laser with sr P947049 and Craig realigned it using a new AR coated lenses.

Attached are the RIN of the OpLev QPD Sum channels.  The ETMY OpLev RIN is much lower than when Gautam took the same measurement yesterday.

Also attached are the pitch and yaw OLG TFs to ensure we still have acceptable phase margins at the UGF.

The last three plots show the optical layout of the ETMY OpLev, a QPD reflection blocker we added to the table, and green light to ETMY not being blocked by any changes to the OpLev.

Quote:

ETMY He/Ne body temp is  ~45 C The laser was seated loosely  in the V-mount with black rubber padding.

The enclosure has a stinky plastic smell from this black plastic. This laser was installed on Oct 5, 2016 See 1 year plot.

Oplev servo turned off. Thermocouple attached to the He/Ne

It will be replaced tomorrow morning.

Quote:

On the control room monitors, I noticed that the IR TEM00 spot was moving around rather a lot in the Y arm. The last time this happened had something to do with the ETMY Oplev, so I took a look at the 30 day trend of the QPD sum, and saw that it was decaying steeply (Steve will update with a long term trend plot shortly). I noticed the RIN also seemed rather high, judging by how much the EPICS channel reading for the QPD sum was jumping around. Attached are the RIN spectra, taken with the OL spot well centered on the QPD and the arms locked to IR. Steve will swap the laser out if it is indeed the cluprit.

 

 

Attachment 1: OpLevRIN24Jan2017.pdf
OpLevRIN24Jan2017.pdf
Attachment 2: ETMYpit_24Jan2017.pdf
ETMYpit_24Jan2017.pdf
Attachment 3: ETMYyaw_24Jan2017.pdf
ETMYyaw_24Jan2017.pdf
Attachment 4: IMG_3510.JPG
IMG_3510.JPG
Attachment 5: IMG_3513.JPG
IMG_3513.JPG
Attachment 6: IMG_3514.JPG
IMG_3514.JPG
  12842   Tue Feb 21 13:51:35 2017 CraigSummaryGeneralAlternative Calibration Scheme

We get SNR in two ways: the amplitude of applied force and the integration time.  So we are limited in two ways: stability of the lock to applied forces and time of locklosses / calibration fluctuations.

At the sites, you probably know that we blow our spectrum out of the water with the calibration lines, with SNRs of about 100 on the scale of about 10 seconds.  For us this might be impossible, since we aren't as quiet.

If we want 1% calibration on our sweeps, we'll need  0.01 = Uncertainty = sqrt( (1 - COH^2)/(2 * Navg * COH^2) ), where COH is the coherence of the transfer function measurement and Navg is the number of measurements at a specific frequency.  This equation comes from Bendat and Piersol, and is subject to a bunch of assumptions which may not be true for us (particularly, that the plant is stationary in time).

If we let Navg = 10, then COH ~ 0.999.

Coherence = Gxy^2/(Gxx * Gyy), where x(t) and y(t) are the input signal and output signal of the transfer function measurement, Gxx and Gyy are the spectral densities of x and y, and Gxy is the cross-spectral density.  

Usually SNR = P_signal / P_noise, but for us SNR = A_signal / A_noise.

Eric Q and Evan H helped me find the relationship between Coherence and SNR:

P = Pn + Pc, Pn = P * (1 - Coh), Pc = P * Coh

==> SNR = sqrt( Pc / Pn ) = sqrt( Coh / 1 - Coh )

From Coh ~ 0.999, SNR ~ 30.

Quote:

Question for Craig: What does the SNR of our lines have to be? IF we're only trying to calibrate the actuator in the audio band over long time scales, it seems we could get by with more frequency noise. Assuming we want a 1% calibration at 50-500 Hz, what is the requirement on the frequency noise PSD curve?

 

  7560   Tue Oct 16 17:13:23 2012 CzarinaSummaryGeneralvent stuff - 4 paths

I see 4+ possible paths for us to take, in terms of a possible vent in the next few weeks:

No Vent - Just do FPPRMI, using AS55

Mini Vent - Fix REFL path, nothing else.  ~1 day at atmosphere

Medium Vent - Fix REFL path, swap G&H mirrors for LaserOptik mirrors (so also resuspend passive TTs, maybe add pitch adjustment option). ~1 week or so at atmosphere - do this rather than Mini if Jan's Finesse calc says the G&H mirrors are too rough

Mega Vent - Fix all the things, do all the things.  Long time at atmosphere

The "+" is to take into account all the possible variations on "medium vent".  The No, Mini and Medium options assume we'll do the Mega option later, just not immediately.

  9855   Fri Apr 25 13:18:08 2014 Dark JamieUpdateLSClocking activity

Quote:

[ericq, Jenne, Zach]

We spent some time tonight trying to push our CARM locking further, to little avail. DARM/CARM loop oscillations kept sneaking up on us. We measured some MC2 motion -> REFL11 Transfer Functions to see if we could see CARM plant features; plots will come in the near future...

 Probably things would have worked better if you would have gotten your hair done at the same place as me.

Attachment 1: m10008_f1_bg.jpg
m10008_f1_bg.jpg
  16897   Tue Jun 7 18:32:46 2022 DeekshaUpdateElectronicsNoise Budgeting ADC (of redpitaya)

Made plots on i/p noise of redpitaya . Need to reconsider sampling frequency (to improve plot at lower freq)
 

Attachment 1: ch1_0.5V.png
ch1_0.5V.png
Attachment 2: ch2_0.0V.png
ch2_0.0V.png
  16939   Wed Jun 22 17:04:06 2022 DeekshaSummaryElectronicsCharacterising the AUX control loop

[Cici, Deekha]

Setup loop to measure transfer function of control loop - the aim is to find the open loop gain of the system using the SR785 to inject noise (a swept sine) into the system and taking observations using the scope. We tried to calculate the gain algaebraically, in order to understand what our readings meant and what we can determine from them. Need to figure out how to run python script for the SR785, but took readings from cmd today.

Included - changes/additions made to circuit; frequency reponse obtained (need to check the frequency response as it does not look like the expected result, need to correct the loop itself, or increase the magnitude of the inserted noise as its possible that the noise is currently being suppressed by the system).

To do - circuit needs to be checked + laser lock improved - laser keeps leaving resonance while trying to take readings.

 

Attachment 1: after.jpeg
after.jpeg
Attachment 2: before.jpeg
before.jpeg
Attachment 3: freq_response.png
freq_response.png
  16951   Mon Jun 27 13:39:40 2022 DeekshaUpdateElectronicsSetting up the MokuLab

[Cici, Deeksha]

On Friday Cici and I set up the Mokulab to take readings of our loop. The aim is to characterise the PZT, in a similar manner as before, by exciting the circuit using our input noise (a swept sine) and recording the corresponding changes in the output. We used the MokuLab to observe the beat note created by the signals of the AUX and PSL, as well as the ASD of the output signal. The MokuLab simplifies the entire process.

Pictured : The beat note as observed by Cici

Attachment 1: WhatsApp_Image_2022-06-24_at_5.21.28_PM.jpeg
WhatsApp_Image_2022-06-24_at_5.21.28_PM.jpeg
  16964   Thu Jun 30 17:19:55 2022 DeekshaSummaryElectronicsMeasured Transfer Functions of the Control Loop, Servo (OLTF); got Vectfit working

[Cici, Deeksha]

We were able to greatly improve the quality of our readings by changing the parameters in the config file (particularly increasing the integration and settle cycles, as well as gradually increasing our excitation signals' amplitude). Attached are the readings taken from the same (the files directly printed by ssh'ing the SR785 (apologies)) - Attachment 1 depicts the graph w/ 30 data points and attachment 2 depicts the graph with 300 data points. 

Cici successfully vectfit to the data, as included in Attachment 3. (This is the vectfit of the entire control loop's OLTF). There are two main concerns that need to be looked into, firstly, the manner in which to get the poles and zeros to input into the vectfit program. Similarly, the program works best when the option to enforce stable poles is disabled, once again it may be worth looking into how the program works on a deeper level in order to understand how to proceed. 

Just as the servo's individual transfer function was taken, we also came up with a  plan to measure the PZT's individual transfer function (using the MokuLab). The connections for the same have been made and the Moku is at the Xend (disconnected). We may also have to build a highpass filter (similar to the one whose signal enters the PZT) to facilitate taking readings at high frequencies using the Moku. 

Attachment 1: TFSR785_29-06-2022_114042.pdf
TFSR785_29-06-2022_114042.pdf
Attachment 2: TFSR785_29-06-2022_114650.pdf
TFSR785_29-06-2022_114650.pdf
Attachment 3: TF_OLG_vectfit.png
TF_OLG_vectfit.png
  16974   Wed Jul 6 18:51:20 2022 DeekshaUpdateElectronicsMeasuring the Transfer Function of the PZT

Yesterday, we set up the loop to measure the PZT of the transfer function - the MokuLab sends an excitation (note - a swept sine of 1.0 V) to the PZT. The cavity is locked to the PSL and the AUX is locked to the cavity. In order to measure the effect of our excitation, we take the beat note of the PSL and the AUX. This gives us a transfer function as seen in Attachment 1. The sampling rate of the MokuLab is set to 'ultrafast' (125kHz), so we can expect accurate performance upto 62.5kHz, however, in order to improve our readings beyond this frequency, modifications must be made to the script (MokuPhaseMeterTF) to avoid aliasing of the signal. A script should also be written to obtain and plot the coherence between the excitation and our output. 

Also attached are - Attachment 2 -  the circuit diagram of the setup, and Attachment 3 - the TF data calculated.

Edit - the SR560 as shown in the circuit diagram has since been replaced by a broadband splitter (Minicircuits ZFRSC-42-S+).

Attachment 1: pzt_transfer_fn.png
pzt_transfer_fn.png
Attachment 2: ckt_diagram.jpeg
ckt_diagram.jpeg
Attachment 3: MokuPhaseMeterTFData_20220706_174753_TF_Data.txt
2.000000000000000364e+04 1.764209350625748560e+07 2.715833132756984014e+00
1.928351995884991265e+04 1.695301366919569671e+07 1.509398637395631626e+00
1.859270710016814337e+04 1.647055321367538907e+07 -2.571975165101855865e+00
1.792664192275710593e+04 1.558169995329630189e+07 6.272729335836754183e-01
1.728443786563210961e+04 1.500850042360494658e+07 -1.500422400597591466e+00
1.666524012797089381e+04 1.456986577652360499e+07 2.046163000975175894e+00
1.606822453133765885e+04 1.376167843637173250e+07 1.736835046956476614e+00
1.549259642266657283e+04 1.326192932667389885e+07 -1.272425049850132606e+00
1.493758961654484847e+04 1.283127345074228011e+07 -2.026149685362535369e+00
1.440246537538758821e+04 1.208854709974890016e+07 -3.248352694840740407e-01
... 11 more lines ...
  17031   Mon Jul 25 09:37:39 2022 DeekshaUpdateElectronicsUsing the DFD to measure PZT TF

The DFD was setup to measure the change in beatnote when excited. A long long (128in) cable goes from the SR785 near the DFD all the way to the Xend AUX which it accordingly excites and the DFD is monitored by the oscilloscope at the other end. This was completed on Friday. The wires and stand have been moved to the side but the setup is still a bit chaotic. As of writing this post, there is still atleast some minor issue with the setup as we aren't getting the expected output. 

[I will shortly update this elog with more pictures]

Edit: the SR785 was replaced by the AG 4395, and pictures added

 

Attachment 1: ag4395.jpeg
ag4395.jpeg
Attachment 2: dfd.jpeg
dfd.jpeg
  17035   Mon Jul 25 18:22:30 2022 DeekshaSummaryWikiMeasured the PZT TF Successfully

Measured the PZT beatnote using the setup mentioned in elog post 17031. Attached is the data taken from 10kHz to 1MHz, decadewise data was also taken that I'm not including in this post. A_R refers to the transfer function taken of channel A wrt the voltage reference (the swept sine we are inputting which has an IF of 30kHz). A and B correspond to the I and Q components of the signal taken from the DFD, respectively. I am currently working on plotting the data, and will shortly update this post with plots. Next steps - 

- quantify the uncertainty in the signal (I think)

- vectfit the data to find poles and zeroes

(and possibly find a better way to print/obtain data)

Edit: first pass of data plotted

Attachment 1: A_R_MAG.txt
"4395A REV1.12"
"DATE: Sep 17 2017"



"CHANNEL: 1"
"MEASURE TYPE: A/R"
"FORMAT TYPE: LOG MAG"
"NUMBER of POINTS: 801"
"SWEEP TIME:  385.3 ms"
... 811 more lines ...
Attachment 2: A_R_PHASE.txt




"CHANNEL: 2"
"MEASURE TYPE: A/R"
"FORMAT TYPE: PHASE (DEG)"
"NUMBER of POINTS: 801"
"SWEEP TIME:  385.3 ms"
... 808 more lines ...
Attachment 3: B_R_MAG.txt
"4395A REV1.12"
"DATE: Sep 17 2017"



"CHANNEL: 1"
"MEASURE TYPE: B/R"
"FORMAT TYPE: LOG MAG"
"NUMBER of POINTS: 801"
"SWEEP TIME:  385.3 ms"
... 809 more lines ...
Attachment 4: B_R_PHASE.txt




"CHANNEL: 2"
"MEASURE TYPE: B/R"
"FORMAT TYPE: PHASE (DEG)"
"NUMBER of POINTS: 801"
"SWEEP TIME:  385.3 ms"
... 807 more lines ...
Attachment 5: freq_resp_I.png
freq_resp_I.png
Attachment 6: freq_resp_Q.png
freq_resp_Q.png
  17036   Tue Jul 26 19:50:25 2022 DeekshaUpdateComputer Scripts / ProgramsVector fitting

Trying to vectfit to the data taken from the DFD previously but failing horribly. I will update this post as soon as I get anything semi-decent. For now here is this fit.

Attachment 1: data.png
data.png
Attachment 2: fit_attempt.png
fit_attempt.png
  17039   Wed Jul 27 14:39:04 2022 DeekshaUpdateElectronicsNew and improved PZT TF data from the DFD

Paco and I messed around with the attenuation of the scope and bandwidth of the IF. We also replaced the BNC T's in the circuits with RF splitters. We saw some decent improvements to the data. The data is attached and a diagram of the experiment. [We analytically calculated the impedances to avoid any mismatch taking place]. Working on fitting the data.

We also moved around the wires so that the AG4395 is closer to the PZT.

 

Attachment 1: tf_data.png
tf_data.png
Attachment 2: latest_data.zip
Attachment 3: dfd_-_new.drawio.png
dfd_-_new.drawio.png
  5573   Thu Sep 29 00:16:35 2011 DenUpdateComputersSegmentation fault fixed.

The OAF c-code crashed because of the segmentation fault. We've created arrays of static variables

    static int pst[nDOF];
    static int isFirst[nDOF];
    static adaptive_filter_state state[nDOF];

an tried to give in the to the ITERATE - function their current values

        datOut[i] = ITERATE(iterateDatIn, iterateNIn, pst[i], isFirst[i], state[i]);

ITERATE function was declared as

double ITERATE(double *datIn, int nIn, int pst, int isFirst, adaptive_filter_state state) {}

Here the segmentation fault comes out. Static variables are meant to be created only once but here in the function ITERATE we try to create them once again in a local form, because we give the variables by their values.

Instead, we must give the variables by their pointer, then the variables won't be created again during the function call and will be changed in the function.

        datOut[i] = ITERATE(iterateDatIn, iterateNIn, &pst[i], &isFirst[i], &state[i]);

       double ITERATE(double *datIn, int nIn, int *pst_s, int *isFirst_s, adaptive_filter_state *state_s)

In order not to change significantly Matt's code and use his notations we can add in the ITERATE function

    int pst = *pst_s;
    int isFirst = *isFirst_s;
    static adaptive_filter_state state;
    state = *state_s;

..................................Matt's code.........................................

    *pst_s = pst;
    *isFirst_s = isFirst;
    *state_s = state;

I've tested the program, now it does not give any segmentation faults and conserves memory that it uses.

  5740   Tue Oct 25 21:49:13 2011 DenUpdateAdaptive FilteringAdaptive filter witness and EP SNR

Quote

Coherence of seismometers to MCL:


STS1 is located at the vertex. x-axis along the x arm.
GUR1 is located at the IMC MC2 mirror. Same orientation.
Coherence.png

=> 1. Only the x-direction has good coherence (to be expected)
     2. Only good coherence at 1.5-4Hz (huh?)

So probably other noise sources are dominating. Let's look into noise projections. Remember IMC autoalignment is off.

A quick adaptive filter run with only the GUR1 and STS1 witnesses applied only to MCL didn't really do anything. Some more thought needs to be invested into the AA and shaping filters.

Indeed, only GUR1_X is reasonable. Static Wiener filtering (length = 2500) of MCL with witness channels GUR_1_X, GUR_1_Y, GUR_1_Z proves your measurements.

We need to callibrate seimometers. I think that now we see velocity, not displacement. It might be useful to amplify the seimometer singal before ADC to make sure that our signal is not ADC noise.

Attachment 1: gur1_x.jpg
gur1_x.jpg
Attachment 2: gur1_y.jpg
gur1_y.jpg
Attachment 3: gur1_z.jpg
gur1_z.jpg
  5777   Tue Nov 1 18:16:50 2011 DenUpdateAdaptive FilteringAdaptive filter witness and EP SNR

Quote:

 

Coherence of seismometers to MCL:


STS1 is located at the vertex. x-axis along the x arm.
GUR1 is located at the IMC MC2 mirror. Same orientation.
Coherence.png

=> 1. Only the x-direction has good coherence (to be expected)
     2. Only good coherence at 1.5-4Hz (huh?)

So probably other noise sources are dominating. Let's look into noise projections. Remember IMC autoalignment is off.

A quick adaptive filter run with only the GUR1 and STS1 witnesses applied only to MCL didn't really do anything. Some more thought needs to be invested into the AA and shaping filters.

The possible explanation to this effect is the following:

Seismic noise mainly consists of the Love and Rayleigh surface waves. In the simulations we've taken 2 perpendicular Love waves and 2 perpendicular Rayleigh waves that interfere under the test mirrors. This interference produces both translational and tilt movements. Then we can see the coherence between translational motion and cavity length.

translation_length.jpg

1. The coherence at big frequencies is small due to the passive isolation.

2. The coherence at 1 Hz is 0 due to the wire resonance.

3. The coherence between 1 and 10 Hz is reasonable. At the real 40m's measurements we can see only good coherence for gur1_x and sts1_x but this is the matter of adjusting seismic waves amplitude and direction. In the simulation we've assumed that all waves are of the same amplitude. The really interesting thing is that

4. The coherence below 0.8 Hz began to grow. We don't see this in real measurements.

But let's simulate the seismometer measurements. It measures not only translational motion but also tilt and with amplitude proportional to g / omega^2. On the Figure below the spectrum of translation motion, tilt and tilt as seen by seismometer is presented. We can see that at low frequencies tilt begins to dominate over the translational motion. We assumed the speed of waves in the region 30 - 60 m/sec.

trans_tilt.jpg

Let's now plot the coherence between the cavity length and seismometer signal.

seismic_length.jpg

We can see that the coherence between seismic signal from measured by seismometer and cavity length is gone below 1 Hz where tilt becomes important.

Now let's try to filter out the seismic noise from the cavity length using both static Wiener filtering and adaptive Mfxlms algorithm. For both filters we've used AA filter before the filters and also AI filter after adaptive filter. The downsampling ratio was 4, the sample frequency 256. We can see that nothing is really subtracted due to the pollution of the seismometer signal due to tilt motion.

tilt_filtering.jpg

Assume we do the same computational experiment but with the seismometers that measure only ground translational motion and tilt do not affect on them. Then we have a reasonable subraction of seismic noise at low frequencies even with the filters of the length 100 as shown on the figure below.

filtering.jpg

Let's look through an order of magnitude analysis. Assume ground motion consists of only one wave with amplitude A and only vertical movement:  z(t) = A*sin(2 pi 0.1 t). So the frequency of the wave is 0.1 Hz. If A = 10-6 m => the amplitude of the suspended mirror motion is also approximately 10-6 m, as we have no isolation at low frequencies. The tilt angle has the amplitude alpha = 2*pi*A/lambda, where lambda - wavelength of the ground wave, lambda = v/f = 40/0.1 = 400 m, v - speed of the wave, f - frequency. Then alpha = 10-8 rad. If the distance between ground and mirror suspension point is 1 m, then mirror motion amplitude due to tilt is B = 10-8 m << A. 
It turns out that tilt does not effect much on the cavity length compared to the ground translational motion, but it affects a lot on the seismometer signals, that are used as witness signals in the filtering. For that reason we need tiltmeters to filter seismometer signals in order to obtain pure translational ground motion.
  5816   Fri Nov 4 21:52:58 2011 DenUpdateAdaptive Filteringcoherence

[Mirko, Den]

We still think about the coherence between seismic noise and mode cleaner length. We beleive that

1. Below ~0.1 Hz tilt affects on the seismometers as was simulated http://nodus.ligo.caltech.edu:8080/40m/5777

2. From 0.1 to 1 Hz is an interesting region. We try to figure out why we do not see any coherence here. Tilt does not seem to dominate.

At 1 Hz coherence might be lost because of the sharp resonance. For example, if the mirror is suspended to the platform by wires with f = 1 Hz and Q = 1000, then the coherence between platform motion and mirror motion will be lost as shown on the figure below.

mirror_platform.jpg

For this reason we tried to "help" to the adaptive filter to guess transfer function between the ground motion and mirror motion by multiplying seimometer signal by the platform -> mirror transfer function. As we do not know exactly eigen frequency and Q of the wires, we did a parametric simulation as shown on the figure below

coherence.jpg

The maximum coherence that we could achieve with treak was 0.074 compared to 0.056 without. This was achieved at f=1.0011 Hz but with surprisingly high Q = 330. And though this did not help, we should keep in mind the tecnique of "helping" the adaptive filter to guess the transfer function if we partly know it.

Another unexpected thing is that we see come coherence between gur1_x and mode cleaner WFS pitch signal at frequencies 0.1 - 1 Hz

Screenshot-4.png

 

 

 From this we can suggest that either mode MC_F channel does not completely reflect the mc length at low frequencies or WFS2 shows weard signal.

  5869   Fri Nov 11 00:55:53 2011 DenUpdateAdaptive FilteringMC_F

[Mirko, Den]

Not satisfactory work of adaptive filtering make us to think about the signals that we use. Now we try to deal with mode cleaner and analize its length. We take MC_F channel. We know that MC_F is used as a feedback signal to the laser frequency and laser changes it's frequency linear to the input modulation signal up to ~1kHz. Than is MC_F is length of MC, not velocity or acceleration. If so, it's form due to seismic noise + company of other noises + stacks and wires should be approximately like the left plot. Instead we see the right plot.

mcl_sim.jpgmcl_real.jpg

 

Possibly, left-plot form signal is not possible to transmit through the wires and adc. Most signal at medium and high frequencies would be lost because of wire and adc noise. For that reason mode cleaner length signal might be amplified at frequecnies >~20 Hz by some bandpass filter.

Where is this highpass filter and what is the form of this filter?

It might be just after the photodetector in order not to transmit real mode cleaner length through the wires. But if wires and not very noisy, it could be somewhere before ADC.

But anyway, for the laser frequency feedback the corresponding low pass filter should be used.

Where is this lowpass filter and what is the form of the filter?

We followed the mode cleaner length signal up to TT FSS and measured the mode cleaner length, that is used as an input to TT FSS. As shown http://nodus.ligo.caltech.edu:8080/40m/5867 MC_F is different from the signal that is given to TT FSS. This is not clear because we do not have smth that could effect on the signal that much before branch node and recording of MC_F. The main difference is the cut off at the MC_F signal at 3 Hz. It might be a digital filter but we do not see any filters between adc_0_0 up to MC_F test point - straight line. This means that we have an analog filter somewhere between that blue box where the branch point is and ADC. We need to find it. But at least, we do not have a lowpass filter before FSS. So it is probably after it.

So, we need to find the 3 filters that we think affect on the MC_F channel in order to figure out why we have such a bad coherence between seismic signal and mode cleaner length.

  5870   Fri Nov 11 00:58:19 2011 DenUpdateelogrestarted elog

Elog suspended 2 times for 1 hour. Too high frequency.

Restarted.

  5882   Sat Nov 12 02:46:13 2011 DenUpdateAdaptive Filteringstacks and ground

We measured the coherence between the seismometer near the MC2 stack and accelerometers on the vacuum tank where MC2 is. Because accelerometers produce small signals at low frequencies, which are comparable with adc noise, we  amplified the accelerometer signal by a factor of 20. We could not do it more because though adc has 40 V range, the black box that follows the channel sockets can transmit only 2.5 V max amplitude signal. Probably, this was done because old adc accepted 2 V max amplitude.

ground_stack.jpg

ground_stack_coherence.jpg


We were able to found some coherence at 0.1-1 Hz though the accelerometer signal is rather noisy. So to consider stack as a noise source is still possible. This measurement should be better done with two seismometers, one on the floor, the other on the stack. From the figure we can also see that tilt affects the x and y seismometer signals from 0.1 Hz. Green line (z-component) is much lower that red and blue lines (x and y). Tilt affects on horisontal axes of the seismometer much more than on vertical.

What we also think about is that at low frequencies mirrors start to move approximately the same and seismometers can help us to figure out small reletive displacement of the mirrors which form the MC length. We can estimate the critical frequency by presenting the ground motion as interference of surface waves with different velocities and amplitudes. For only 1 wave we have for the relation of MC length to the seismometer read out  ~sin (2*pi*f/v*L). f - frequency of the wave, v -speed, L - length between the mirrors. We can see that below 1 Hz we have ~sin (f/2). At this point seismometer signal could lose coherence with MC length signal. We could try to subtract seismometer signals from corresponding axes, but gur1 and sts1 has different calibrations. Moreover, the noise floor of the seismometers might not allow us to measure the differential signal. We'll try to simulate this scenario and find seismometer calibration or measure it. We are basicly interested only in the ratio of calibraion fucntions of 2 seismometers.

  5919   Wed Nov 16 23:50:40 2011 DenUpdateAdaptive Filteringseismic noise injection

[Micro, Den]

Analyzing coherence of seismic noise and mode cleaner length we've figured out that at some days the coherence below 1 Hz is still present. For example, at Nov 13 we can see some coherence compared to most other dates when we are not able to see coherence as shown on the figure. On the top plot - psd of MC_L and GUR1_X at Nov 13 (red and blue) and Nov 15 (black and cyan). On the bottom plot is presented coherence between MC_L and GUR1_X on Nov 13 (red) and Nov 15 (black)

datespsd.jpg

datescoh.jpg

We can divide the psd plot for 2 parts - below 1 Hz and above 1 Hz. Above 1 Hz seismic noise on Nov 15 (cyan) was higher then on Nov 13 (blue) and correspondently MC_L at that region was higher on Nov 15. Below 1 Hz seismic noise was higher on Nov 13 but MC_L is still lower that on Nov 15. That is surprising. From the coherence plot we can say that once we have some more seismic noise than usually, we immediately see coherence.

Because of this we wanted to find out the level of the X noise that makes seismic noise invisible. We injected seismic noise by doing smooth physical exercises near MC_2 (1.5 m and 3 m apart). The MC_2 was in lock during the experiment.

injectionpsd.jpg

injectioncoh.jpg

In the coherence plot we can see that coherence between GUR1_X and MC_L increased with noise injection. The highest coherenced we obtained sittind down and standing up smoothly near MC_2 at distance 1.5 m. We did not want to come clother and break the lock. This measurement tells us that the X noise is approximately 3-4 times higher than seismic noise in the range 0.1 - 1 Hz. That means that it is approximately 1e-6 - 1e-8 m/sqrt(Hz) in this region. This noise goes down at frequencies from 2 Hz and not seen because of seismic noise. Actually, seismic noise can be filtered out with the Wiener filter and then we'll see the spectrum of X noise.

We now try to figure out the method to estimate the contribution of OSEM noise to the X noise.

  5932   Thu Nov 17 22:24:19 2011 DenUpdateAdaptive FilteringMC1_COIL

Analyzing coherence between MC length and signals on MC1, MC2 and MC3 coils we have noticed that MC1 COIL signal is not coherent to MC length at all at interesting frequencies 0.1 - 1 Hz.

We try to explain this phenomena.

 

Attachment 1: MC1COIL-crop.pdf
MC1COIL-crop.pdf
Attachment 2: MC2COIL-crop.pdf
MC2COIL-crop.pdf
Attachment 3: MC3COIL-crop.pdf
MC3COIL-crop.pdf
  5933   Thu Nov 17 23:38:40 2011 DenUpdateIOOMC unlocked

MC is unlocked to measure the free swing of the MC mirrors with the local sensors.

Autolocker is disabled.

  5934   Thu Nov 17 23:44:48 2011 DenUpdateIOOMC1_SENSOR

We've found that one of the  MC1_SENSORS does not work properly.

See the figure.

Attachment 1: MCSENSORS.pdf
MCSENSORS.pdf
  5935   Thu Nov 17 23:47:43 2011 DenUpdateIOOMC1_SENSOR

The most interesting plot did not uploaded in the previous elog.

Upload now local MC1_SENSOR signals.

Attachment 1: MC1SENSOR-crop.pdf
MC1SENSOR-crop.pdf
  5939   Fri Nov 18 01:27:04 2011 DenUpdateIOOMC locked

[Mirko, Den]

While the MC was unlocked (and the local damping off) we've measured the coherence between GUR1_X and OSEM sensors. It was rather high, close to 1 at frequencies 0.1 - 1 Hz. That means that stack does not kill all coherence between seismic noise and mirror motion.

Then we've turned on the local damping and measured the coherence again between GUR1_X and OSEM sensors. It decreased due to some noise and was on the level of ~0.5. We did reduced the motion between the mirror and the frame by local damping but it is not obvious that we lost some coherence due to this effect. Probably, actuator adds some noise.

When we locked the MC, we did not see any coherence at 0.1 - 1 Hz between GUR1_X or STS1_X and OSEM sensors of MC1 and MC3 but we did see with MC2. The MC1 sensor was fixed by Suresh.

 

Attachment 1: cohnolocalpumping-crop_4.pdf
cohnolocalpumping-crop_4.pdf
Attachment 2: cohlocalpumping4-crop.pdf
cohlocalpumping4-crop.pdf
Attachment 3: cohlock4-crop.pdf
cohlock4-crop.pdf
  5957   Sat Nov 19 01:26:16 2011 DenUpdateIOOMode cleaner noise projection

Quote:

Instead, what we want is to project how the actual OSEM noise in the presence of no signal shows up as MC length. For that we should use the old traces of the OSEM noise with no magnets and then inject that spectrum of noise into the SUSPOS filter bank with all the loops running. We can then use this TF to estimate the projection of OSEM noise into the MC length.

That's right. The easier problem arises if we consider one of  MC mirrors. The coherence between OSEM sensors and GUR1_X in free moving regime is equal to 0.9 at frequencies 0.1 - 1 Hz. But with local dumping coherence is 0.6. We have

Mirror -> Sensor -> Satellite Module -> Whitening -> ADC -> Computer -> DAC -> Dewhitening -> Satellite Module -> Actuator -> Mirror

Somewhere we produce noise that kills part of coherence. We can use this method with the injection of spectrum of noise into the SUSPOS filter bank only for one mirror and see how the coherence between OSEM sensor and GUR1_X will change. If the change is small, we deal with something else. It the coherence will change from 0.6 to ~0.4, than we have big OSEM noise.

It might be also the problem that the amplitude of COIL_OUT signal is ~25. If it is in counts we may have noise from DAC. 

  6019   Sat Nov 26 19:37:12 2011 DenUpdateGeneralfoton files

 I've checked foton files for small numbers. There are several other filters besides "Cheby" that are presented with small numbers. For example, "BTW0.01" in the LOCKING_Q, LOCKING_I modules,  "SeisDaytime"  in the SUP_MC3_SP_NOISE and others. The output of the commands is presented below.

>chans

>cat C1???.txt | grep e-23

 

SUP_MC3_SP_Y_NOISE 2 12 4  16384      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUP_MC3_SP_YAW_NOISE 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUP_MC3_SP_ROLL_NOISE 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUP_MC3_SP_PIT_NOISE 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUP_MC2_SP_Y_NOISE 2 12 4  16384      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUP_MC2_SP_YAW_NOISE 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUP_MC2_SP_ROLL_NOISE 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUP_MC2_SP_PIT_NOISE 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUP_MC1_SP_Y_NOISE 2 12 4  16384      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUP_MC1_SP_YAW_NOISE 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUP_MC1_SP_ROLL_NOISE 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUP_MC1_SP_PIT_NOISE 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUS_MC3_SUSYAW 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_MC3_SUSSIDE 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_MC3_SUSPOS 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_MC3_SUSPIT 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_MC3_LSC 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_MC2_SUSYAW 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_MC2_SUSSIDE 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_MC2_SUSPOS 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9978637592754149   0.9978663974923444   2.0000000000000000   1.0000000000000000

SUS_MC2_SUSPIT 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_MC1_SUSYAW 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_MC1_SUSSIDE 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_MC1_SUSPIT 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_SRM_SUSYAW 3 12 4  32768      0 Cheby         1.1175580413719e-23    -1.99726998010527     0.99727436063954     2.00000000000000     1.00000000000000

SUS_SRM_SUSPOS 3 12 4  32768      0 Cheby         1.1175580413719e-23    -1.99726998010527     0.99727436063954     2.00000000000000     1.00000000000000

SUS_SRM_SUSPIT 3 12 4  32768      0 Cheby         1.1175580413719e-23    -1.99726998010527     0.99727436063954     2.00000000000000     1.00000000000000

SUS_PRM_SUSYAW 3 12 4  32768      0 Cheby         1.1175580413719e-23    -1.99726998010527     0.99727436063954     2.00000000000000     1.00000000000000

SUS_PRM_SUSPOS 3 12 4  32768      0 Cheby         1.1175580413719e-23    -1.99726998010527     0.99727436063954     2.00000000000000     1.00000000000000

SUS_PRM_SUSPIT 3 12 4  32768      0 Cheby         1.1175580413719e-23    -1.99726998010527     0.99727436063954     2.00000000000000     1.00000000000000

SUS_ETMX_SUSYAW 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_ETMX_SUSSIDE 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_ETMX_SUSPOS 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_ETMX_SUSPIT 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_ETMX_LOCKIN1_I 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

SUS_ETMX_LOCKIN1_Q 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

SUS_ETMX_LOCKIN2_I 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

SUS_ETMX_LOCKIN2_Q 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

SUS_ETMY_SUSYAW 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_ETMY_SUSSIDE 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_ETMY_SUSPOS 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_ETMY_SUSPIT 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SUS_PIT_NOISE_FILT 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUS_ROLL_NOISE_FILT 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUS_YAW_NOISE_FILT 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUS_Y_NOISE_FILT 2 12 4  16384      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUS_PIT_NOISE_FILT 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUS_ROLL_NOISE_FILT 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUS_YAW_NOISE_FILT 2 21 4      0      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

SUS_Y_NOISE_FILT 2 12 4  16384      0 SeisDaytime    4.3736847644382e-23    -1.99994247406600     0.99994247737496    -0.00000000000000    -1.00000000000000

BS_LOCKIN2_Q 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

BS_LOCKIN2_I 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

BS_LOCKIN1_Q 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

BS_LOCKIN1_I 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

BS_SUSPIT 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

BS_SUSPOS 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

BS_SUSSIDE 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

BS_SUSYAW 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

ITMX_LOCKIN2_Q 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

ITMX_LOCKIN2_I 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

ITMX_LOCKIN1_Q 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

ITMX_LOCKIN1_I 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

ITMX_SUSPIT 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

ITMX_SUSPOS 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

ITMX_SUSSIDE 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

ITMX_SUSYAW 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

ITMY_LOCKIN2_Q 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

ITMY_LOCKIN2_I 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

ITMY_LOCKIN1_Q 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

ITMY_LOCKIN1_I 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

ITMY_SUSPIT 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

ITMY_SUSPOS 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

ITMY_SUSSIDE 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

ITMY_SUSYAW 3 21 4      0      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

PRM_LOCKIN2_Q 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

PRM_LOCKIN2_I 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

PRM_SUSPIT 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

PRM_SUSPOS 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

PRM_SUSSIDE 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

PRM_SUSYAW 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SRM_LOCKIN2_Q 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

SRM_LOCKIN2_I 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

SRM_LOCKIN1_Q 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

SRM_LOCKIN1_I 5 21 2      0      0 BTW0.01     1.351815922494362e-23  -1.9999929139431329   0.9999929139578397   2.0000000000000000   1.0000000000000000

SRM_SUSPIT 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SRM_SUSPOS 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

SRM_SUSSIDE 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

 

SRM_SUSYAW 3 12 4  32768      0 Cheby       1.117558041371939e-23  -1.9972699801052749   0.9972743606395355   2.0000000000000000   1.0000000000000000

 
> cat C1???.txt | grep e-21
 
ASS_LOCKIN9_Q 0 21 2      0      0 LP          8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN9_I 0 21 2      0      0 LP          8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN7_Q 0 21 2      0      0 LP          8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN7_I 0 21 2      0      0 LP          8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN29_Q 1 21 2      0      0 LP50m       8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN29_I 1 21 2      0      0 LP50m       8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN27_Q 1 21 2      0      0 LP50m       8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN27_I 1 21 2      0      0 LP50m       8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN24_Q 0 21 2      0      0 LP          8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN24_I 0 21 2      0      0 LP          8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN22_Q 0 21 2      0      0 LP          8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN22_I 0 21 2      0      0 LP          8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN14_Q 1 21 2      0      0 LP50m       8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN14_I 1 21 2      0      0 LP50m       8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN12_Q 1 21 2      0      0 LP50m       8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
ASS_LOCKIN12_I 1 21 2      0      0 LP50m       8.448680182849132e-21  -1.9999645699236510   0.9999645702913159   2.0000000000000000   1.0000000000000000
SUS_SRM_SUSSIDE 3 12 4  32768      0 Cheby         8.6572646852632e-21    -1.99726998010527     0.99727436063954     2.00000000000000     1.00000000000000
SUS_PRM_SUSSIDE 3 12 4  32768      0 Cheby         8.6572646852632e-21    -1.99726998010527     0.99727436063954     2.00000000000000     1.00000000000000
 
> cat C1???.txt | grep e-19
 
SUP_MC3_SP_Z_NOISE 1 21 4      0      0 StackVert     1.8769949851031e-19    -1.99887735863559     0.99888848406943     2.00000000000000     1.00000000000000
SUP_MC2_SP_Z_NOISE 1 21 4      0      0 StackVert     1.8769949851031e-19    -1.99887735863559     0.99888848406943     2.00000000000000     1.00000000000000
SUP_MC1_SP_Z_NOISE 1 21 4      0      0 StackVert     1.8769949851031e-19    -1.99887735863559     0.99888848406943     2.00000000000000     1.00000000000000
SUP_MC1_SP_YAW_NOISE 1 21 4      0      0 StackVert     1.8769949851031e-19    -1.99887735863559     0.99888848406943     2.00000000000000     1.00000000000000
SUP_MC1_SP_ROLL_NOISE 1 21 4      0      0 StackVert     1.8769949851031e-19    -1.99887735863559     0.99888848406943     2.00000000000000     1.00000000000000
SUP_MC1_SP_PIT_NOISE 1 21 4      0      0 StackVert     1.8769949851031e-19    -1.99887735863559     0.99888848406943     2.00000000000000     1.00000000000000
SUS_ETMX_LOCKIN1_I 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000
SUS_ETMX_LOCKIN1_Q 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000
SUS_Z_NOISE_FILT 1 21 4      0      0 StackVert     1.8769949851031e-19    -1.99887735863559     0.99888848406943     2.00000000000000     1.00000000000000
SUS_Z_NOISE_FILT 1 21 4      0      0 StackVert     1.8769949851031e-19    -1.99887735863559     0.99888848406943     2.00000000000000     1.00000000000000
BS_LOCKIN1_Q 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000
BS_LOCKIN1_I 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000
ITMX_LOCKIN1_Q 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000
ITMX_LOCKIN1_I 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000
ITMY_LOCKIN1_Q 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000
ITMY_LOCKIN1_I 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000
PRM_LOCKIN1_Q 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000
PRM_LOCKIN1_I 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000
SRM_LOCKIN1_Q 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000
SRM_LOCKIN1_I 2 21 2      0      0 BTW0.1       1.35175496376953e-19  -1.9999291403672526   0.9999291418378861   2.0000000000000000   1.0000000000000000 
  6029   Mon Nov 28 18:53:35 2011 DenSummaryWienerFilteringseismic noise substraction

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 filter coefficients. Then you automatically have Wiener filter ouput + adaptively control coefficients. But if Wiener filter is already present in the model, I tried to make it work. Then we can compare performance of the OAF with static filter and without it.

I started with GUR1_X and MC_F signals recorded 1 month ago to figure out how stable TF is. Will the same coefficients work now online? In the plot below offline Wiener filtering is presented.

gur1_x.jpg

 

This offline filtering was done with 7500 coefficients. This FIR filter was converted to IIR filter with the following procedure:

1. Calculate frequency responce of the filter. It is presented below.

filter_response.jpg

2. Multiply this frequency response by a window function. This we need because we are interested in frequencies 0.1-20 Hz at this moment. We want this function to be > 1e-3 at ~0Hz, so that the DC component is filtered out from seismometer signal. From the other hand we also do not want huge signal at high frequenies. We know that this signal will be filtered with aggresive low-pass filterd before going to the actuator but still we want to make sure that this signal is not very big to be filtered out by the low-pass filter.

The window function is done in the way to be a differential function to be easier fitted by the vectfit3. Function is equal to 1 for 0.5 - 20 Hz and 1e-5 for other frequencies except neighbouring to the 0.5 and 20 where the function is cosine.

window.jpg

3. I've used vectfit3 software to approximate the product of the frequency response of the filter and window fucntion with the rational function. I've used 10 complex conjugate poles. The function was weighted in the way to make deviation as small as possible for interesting frequencies 0.5 - 10 Hz. The approximation error is big below 20 Hz where the window function is 1e-5 but at least obtained rational function does not increase as real function do at high frequencies.

filter_fitting.jpg

I tried to make a foton filter out of this approximation but it turns out that this filter is too large for it. Probably there is other problem with this approximation but once I've split the filter into 2 separate filters foton saved it. Wiener21 and Wiener22 filters are in the C1OAF.txt STATIC_STATMTX_8_8 model.

I've tested how the function was approximated. For this purpose I've downloaded GUR and MC_F signals and filtered GUR singla with rational approximation of the Wiener filter frequency response. From power spectral density and coherence plots presented below we can say that approximation is reasonable.

zpk_wiener.jpgzpk_wiener_coh.jpg

Next, I've approximated the actuator TF and inverted it. If TF measured in p. 5900 is correct then below presented its  rational approximation. We can see deviation at high frequencies - that's because I used small weights there using approximation - anyway this will not pass through 28 Hz low-pass filter before the actuator.

 actuator_fitting.jpg

I've inverted this TF p->z , z->p, k->1/k. I've also added "-" sign before 1/k because we subtract the signal, not add it. I placed this filter 0.5Actuator20 to the C1OAF.txt SUS-MC2_OUT filter bank.

The next plot compares online measured MC_L without static filtering and with it. Blue line - with online Wiener filtering, red line - without Wiener filtering.

wiener_mcl-crop.pdf

We can see some subtraction in the MC_L due to the static Wiener filtering in the 2-5 Hz where we see coherence. It is not that good as offline but the effect is still present. Probably, we should measure the actuator TF more precisely. It seems that there some phase problems during the subtraction. Or may be digital noise is corrupting the signal. 

Attachment 4: filter_fitting.jpg
filter_fitting.jpg
  6038   Tue Nov 29 15:57:43 2011 DenUpdateCDSlocation of currently used filter function

 

We are interested in the following question : Can the structures defined in fm10Gen.h (or some other *.c *.h files with defined as FLOAT variables) create single precision instead of double in the filter calculations?

 

typedef struct FM_OP_IN{
  UINT32 opSwitchE;     /* Epics Switch Control Register; 28/32 bits used*/
  UINT32 opSwitchP;     /* PIII Switch Control Register; 28/32 bits used*/
  UINT32 rset;          /* reset switches */
  float offset;         /* signal offset */
  float outgain;        /* module gain */
  float limiter;        /* used to limit the filter output to +/- limit val */
  int rmpcmp[FILTERS];  /* ramp counts: ramps on a filter for type 2 output*/
                        /* comparison limit: compare limit for type 3 output*/
                        /* not used for type 1 output filter */
  int timeout[FILTERS]; /* used to timeout wait in type 3 output filter */
  int cnt[FILTERS];     /* used to keep track of up and down cnt of rmpcmp */
                        /* should be initialized to zero */
  float gain_ramp_time; /* gain change ramping time in seconds */
} FM_OP_IN;  

 

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