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ID Date Author Type Category Subject
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.

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.

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.

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.

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.

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.

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.

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
13427   Tue Nov 14 16:02:43 2017 KiraSummaryPEMseismometer can testing

I made a model for our seismometer can using actual data so that we know approximately what the time constant should be when we test it out. I used the appendix in Megan Kelley's report to make a relation for the temperature in terms of time.

$\frac{dQ}{dt}=mc\frac{dT(t)}{dt}$ so $T(t)=\frac{1}{mc}\int \frac{dQ}{dt}dt=\frac{1}{mc}\int P_{net}dt$ and $P_{net}=P_{in}-P_{out}$

In our case, we will heat the can to a certain temerature and wait for it to cool on its own so $\inline P_{in}=0$

We know that $\inline P_{out}=\frac{kA\Delta T}{d}$ where k is the k-factor of the insulation we are using, A is the area of the surface through which heat is flowing, $\inline \Delta T$ is the change in temperature, d is the thickness of the insulation.

Therefore,

$T(t)=\frac{1}{mc}\int_{0}^{t}\frac{kA}{d}[T_{lab}-T(t')]dt'=\frac{kA}{mcd}(T_{lab}t-\int_{0}^{t}T(t')dt')$

We can take the derivative of this to get

$T'(t)=\frac{kAT_{lab}}{mcd}-\frac{kA}{mcd}T(t)$, or $T'(t)=B-CT(t)$

We can guess the solution to be

$T(t)=C_{1}e^{-t/\tau}+C_{2}$ where tau is the time constant, which we would like to find.

The boundary conditions are $\inline T(0)=40$ and $\inline T(\infty)=T_{lab}=24$. I assumed we would heat up the can to 40 celcius while the room temp is about 24. Plugging this into our equations,

$\inline C_{1}+C_{2}=40, C_{2}=24$, so $\inline C_{1}=16$

We can plug everything back into the derivative T'(t)

$T'(t)=-\frac{16}{\tau}e^{-t/\tau}=B-C[16e^{-t/\tau}+24]$

Equating the exponential terms on both sides, we can solve for tau

$\frac{16}{\tau}e^{-t/\tau}=16Be^{-t/\tau}, \frac{1}{\tau}=B, \tau=\frac{1}{B}=\frac{mcd}{kA}$

Plugging in the values that we have, m = 12.2 kg, c = 500 J/kg*k (stainless steel), d = 0.1 m, k = 0.26 W/(m^2*K), A = 2 m^2, we get that the time constant is 0.326hr. I have attached the plot that I made using these values. I would expect to see something similar to this when I actually do the test.

To set up the experiment, I removed the can (with Steve's help) and will place a few heating pads on the outside and wrap the whole thing in a few layers of insulation to make the total thickness 0.1m. Then, we will attach the heaters to a DC source and heat the can up to 40 celcius. We will wait for it to cool on its own and monitor the temperature to create a plot and find the experimental time constant. Later, we can use the heatng circuit we used for the PSL lab and modify the parts as needed to drive a few amps through the circuit. I calculated that we'd need about 6A to get the can to 50 celcius using the setup we used previously, but we could drive a smaller current by using a higher heater resistance.

Attachment 1: time_const.png
13438   Tue Nov 21 16:00:05 2017 KiraUpdatePEMseismometer can testing

I performed a test with the can last week with one layer of insulation to see how well it worked. First, I soldered two heaters together in series so that the total resistance was 48.6 ohms. I placed the heaters on the sides of the can and secured them. Then I wrapped the sides and top of the can in insulation and sealed the edges with tape, only leavng the handles open. I didn't insulate the bottom. I connected the two ends of the heater directly into the DC source and drove the current as high as possible (around 0.6A). I let the can heat up to a final value of 37.5C, turned off the current and manually measured the temperature, recoding the time every half degree. I then plotted the results, along with a fit. The intersection of the red line with the data marks the time constant and the temperature at which we get the time constant. This came out to be about 1.6 hours, much longer than expected considering that onle one layer instead of four was used. With only one layer, we would expect the time constant to be about 13 min, while for 4 layers it should be 53 min (the area A is 0.74 m^2 and not 2 m^2).

 Quote: I made a model for our seismometer can using actual data so that we know approximately what the time constant should be when we test it out. I used the appendix in Megan Kelley's report to make a relation for the temperature in terms of time. $\frac{dQ}{dt}=mc\frac{dT(t)}{dt}$ so $T(t)=\frac{1}{mc}\int \frac{dQ}{dt}dt=\frac{1}{mc}\int P_{net}dt$ and $P_{net}=P_{in}-P_{out}$ In our case, we will heat the can to a certain temerature and wait for it to cool on its own so $\inline P_{in}=0$ We know that $\inline P_{out}=\frac{kA\Delta T}{d}$ where k is the k-factor of the insulation we are using, A is the area of the surface through which heat is flowing, $\inline \Delta T$ is the change in temperature, d is the thickness of the insulation. Therefore, $T(t)=\frac{1}{mc}\int_{0}^{t}\frac{kA}{d}[T_{lab}-T(t')]dt'=\frac{kA}{mcd}(T_{lab}t-\int_{0}^{t}T(t')dt')$ We can take the derivative of this to get $T'(t)=\frac{kAT_{lab}}{mcd}-\frac{kA}{mcd}T(t)$, or $T'(t)=B-CT(t)$  We can guess the solution to be $T(t)=C_{1}e^{-t/\tau}+C_{2}$ where tau is the time constant, which we would like to find. The boundary conditions are $\inline T(0)=40$ and $\inline T(\infty)=T_{lab}=24$. I assumed we would heat up the can to 40 celcius while the room temp is about 24. Plugging this into our equations, $\inline C_{1}+C_{2}=40, C_{2}=24$, so $\inline C_{1}=16$ We can plug everything back into the derivative T'(t) $T'(t)=-\frac{16}{\tau}e^{-t/\tau}=B-C[16e^{-t/\tau}+24]$ Equating the exponential terms on both sides, we can solve for tau $\frac{16}{\tau}e^{-t/\tau}=16Be^{-t/\tau}, \frac{1}{\tau}=B, \tau=\frac{1}{B}=\frac{mcd}{kA}$ Plugging in the values that we have, m = 12.2 kg, c = 500 J/kg*k (stainless steel), d = 0.1 m, k = 0.26 W/(m^2*K), A = 2 m^2, we get that the time constant is 0.326hr. I have attached the plot that I made using these values. I would expect to see something similar to this when I actually do the test. To set up the experiment, I removed the can (with Steve's help) and will place a few heating pads on the outside and wrap the whole thing in a few layers of insulation to make the total thickness 0.1m. Then, we will attach the heaters to a DC source and heat the can up to 40 celcius. We will wait for it to cool on its own and monitor the temperature to create a plot and find the experimental time constant. Later, we can use the heatng circuit we used for the PSL lab and modify the parts as needed to drive a few amps through the circuit. I calculated that we'd need about 6A to get the can to 50 celcius using the setup we used previously, but we could drive a smaller current by using a higher heater resistance.

Attachment 1: cooling_fit.png
Attachment 2: IMG_20171121_164835.jpg
13446   Wed Nov 22 12:13:15 2017 KiraUpdatePEMseismometer can testing

Updated some values, most importantly, the k-factor. I had assumed that it was in the correct units already, but when converting it to 0.046 W/(m^2*K) from 0.26 BTU/(h*ft^2*F), I got the following plot. The time constant is still a bit larger than what we'd expect, but it's much better with these adjustments.

For our next steps, I will measure the time constant of the heater without any insulation and then decide how many layers of it we will need. I'll need to construct and calibrate a temperature sensor like the ones I've made before and use it to record the values more accurately.

Quote:

I performed a test with the can last week with one layer of insulation to see how well it worked. First, I soldered two heaters together in series so that the total resistance was 48.6 ohms. I placed the heaters on the sides of the can and secured them. Then I wrapped the sides and top of the can in insulation and sealed the edges with tape, only leavng the handles open. I didn't insulate the bottom. I connected the two ends of the heater directly into the DC source and drove the current as high as possible (around 0.6A). I let the can heat up to a final value of 37.5C, turned off the current and manually measured the temperature, recoding the time every half degree. I then plotted the results, along with a fit. The intersection of the red line with the data marks the time constant and the temperature at which we get the time constant. This came out to be about 1.6 hours, much longer than expected considering that onle one layer instead of four was used. With only one layer, we would expect the time constant to be about 13 min, while for 4 layers it should be 53 min (the area A is 0.74 m^2 and not 2 m^2).

 Quote: I made a model for our seismometer can using actual data so that we know approximately what the time constant should be when we test it out. I used the appendix in Megan Kelley's report to make a relation for the temperature in terms of time. $\frac{dQ}{dt}=mc\frac{dT(t)}{dt}$ so $T(t)=\frac{1}{mc}\int \frac{dQ}{dt}dt=\frac{1}{mc}\int P_{net}dt$ and $P_{net}=P_{in}-P_{out}$ In our case, we will heat the can to a certain temerature and wait for it to cool on its own so $\inline P_{in}=0$ We know that $\inline P_{out}=\frac{kA\Delta T}{d}$ where k is the k-factor of the insulation we are using, A is the area of the surface through which heat is flowing, $\inline \Delta T$ is the change in temperature, d is the thickness of the insulation. Therefore, $T(t)=\frac{1}{mc}\int_{0}^{t}\frac{kA}{d}[T_{lab}-T(t')]dt'=\frac{kA}{mcd}(T_{lab}t-\int_{0}^{t}T(t')dt')$ We can take the derivative of this to get $T'(t)=\frac{kAT_{lab}}{mcd}-\frac{kA}{mcd}T(t)$, or $T'(t)=B-CT(t)$  We can guess the solution to be $T(t)=C_{1}e^{-t/\tau}+C_{2}$ where tau is the time constant, which we would like to find. The boundary conditions are $\inline T(0)=40$ and $\inline T(\infty)=T_{lab}=24$. I assumed we would heat up the can to 40 celcius while the room temp is about 24. Plugging this into our equations, $\inline C_{1}+C_{2}=40, C_{2}=24$, so $\inline C_{1}=16$ We can plug everything back into the derivative T'(t) $T'(t)=-\frac{16}{\tau}e^{-t/\tau}=B-C[16e^{-t/\tau}+24]$ Equating the exponential terms on both sides, we can solve for tau $\frac{16}{\tau}e^{-t/\tau}=16Be^{-t/\tau}, \frac{1}{\tau}=B, \tau=\frac{1}{B}=\frac{mcd}{kA}$ Plugging in the values that we have, m = 12.2 kg, c = 500 J/kg*k (stainless steel), d = 0.1 m, k = 0.26 W/(m^2*K), A = 2 m^2, we get that the time constant is 0.326hr. I have attached the plot that I made using these values. I would expect to see something similar to this when I actually do the test. To set up the experiment, I removed the can (with Steve's help) and will place a few heating pads on the outside and wrap the whole thing in a few layers of insulation to make the total thickness 0.1m. Then, we will attach the heaters to a DC source and heat the can up to 40 celcius. We will wait for it to cool on its own and monitor the temperature to create a plot and find the experimental time constant. Later, we can use the heatng circuit we used for the PSL lab and modify the parts as needed to drive a few amps through the circuit. I calculated that we'd need about 6A to get the can to 50 celcius using the setup we used previously, but we could drive a smaller current by using a higher heater resistance.

Attachment 1: cooling_fit_1.png
13447   Wed Nov 22 14:47:03 2017 KiraUpdatePEMseismometer can testing

For the insulation, I have decided to use this one (Buna-N/PVC Foam Insulation Sheets). We will need 3 of the 1 inch plain backing ones (9349K4) to wrap a few layers around it. I'll try two layers for now, since the insulation seems to be doing quite well according to initial testing.

 Quote: Updated some values, most importantly, the k-factor. I had assumed that it was in the correct units already, but when converting it to 0.046 W/(m^2*K) from 0.26 BTU/(h*ft^2*F), I got the following plot. The time constant is still a bit larger than what we'd expect, but it's much better with these adjustments. For our next steps, I will measure the time constant of the heater without any insulation and then decide how many layers of it we will need. I'll need to construct and calibrate a temperature sensor like the ones I've made before and use it to record the values more accurately.

13455   Tue Nov 28 16:02:32 2017 ranaUpdatePEMseismometer can testing

I've ordered 4 of these from McMaster. Should be delivered to the 40m by noon tomorrow.

 Quote: For the insulation, I have decided to use this one (Buna-N/PVC Foam Insulation Sheets). We will need 3 of the 1 inch plain backing ones (9349K4) to wrap a few layers around it. I'll try two layers for now, since the insulation seems to be doing quite well according to initial testing.

Kira and I also discussed the issiue. It would be good if someone can hunt aroun on the web and get some free samples of non-shedding foam with R~4.

13756   Tue Apr 17 09:57:09 2018 SteveUpdateGeneralseismometer interfaces

 Quote: I've been looking into recovering the seismic BLRMs for the BS Trillium seismometer. It looks like the problem is probably in the anti-aliasing board. There's some heavy stuff sitting on top of it in the rack, so I'll take a look at it later when someone can give me a hand getting it out. In detail, after verifying that there are signals coming directly out of the seismometer, I tried to inject a signal into the AA board and see it appear in one of the seismometer channels. I looked specifically at C1:PEM-SEIS_BS_Z_IN1 (Ch9), C1:PEM-SEIS_BS_X_IN1 (Ch7), and C1:PEM-ACC_MC2_Y_IN1 (Ch27). All of these channels have between 2000--3000 cts. I tried injecting a 200 mVpp signal at 1.7862 Hz into each of these channels, but the the output did not change. All channels have 0 cts when the power to the AA board is off. I then tried to inject the same signal into the AA board and see it at the output. The setup is shown in the first attachment. The second BNC coming out of the function generator is going to one of the AA board inputs; the 32 pin cable is coming directly from the output. All channels give 4.6 V when when the board is powered on regardless of wheter any signal is being injected. To verify that the AA board is likely the culprit, I also injected the same signals directly into the ADC. The setup is shown in the second attachment. The 32 pin cable is going directly to the ADC. When injecting the same signals into the appropriate channels the above channels show between 200--300 cts, and 0 cts when no signal is injected.

Attachment 1: BS_Tril_Intrf-1X5.jpg
Attachment 2: Gurs_Intf-1X1.jpg
13763   Wed Apr 18 20:33:19 2018 KevinUpdateGeneralseismometer interfaces

Steve, the pictures you posted are not the AA board I was referring to. The attached pictures show the board which is sitting beneath the GPS time server.

Attachment 1: front.jpg
Attachment 2: back.jpg
Attachment 3: connectors.jpg
8456   Mon Apr 15 16:10:52 2013 DenUpdatePEMseismometer isolation kit

We got granite bases today from the manufacturer. We plan to set them up on Wednesday, 8 am. Please note, there will be an installation mess at Xend, Yend and corner during ~4 hours. Let us know if you have any objections to do this at this particular time.

Installation locations are specified in elog 8270, scheme attached is valid except for Xend. Instrument will be installed on the place of nitrogen containers.

(  next to the wall at corner sout-east of the south end )

8461   Thu Apr 18 15:08:14 2013 SteveUpdatePEMseismometer isolation kit in place

 Quote: We got granite bases today from the manufacturer. We plan to set them up on Wednesday, 8 am. Please note, there will be an installation mess at Xend, Yend and corner during ~4 hours. Let us know if you have any objections to do this at this particular time. Installation locations are specified in elog 8270, scheme attached is valid except for Xend. Instrument will be installed on the place of nitrogen containers. (  next to the wall at corner sout-east of the south end )

The carpenter shop finished the installation of the 3 granite bases.Rapid Set Cement All high strength non-shrink grout was used.

Compressive strength  3000 PSI at 1 hour and 9000 PSI at day 28 The janitor is still cleaning up after them at the south end.

The  soft silicon gas kits are working well with the SS can.  Den is making  the adaptor plate drawing for the feedthrough.

Attachment 1: grouting1.jpg
Attachment 2: grouting2.jpg
Attachment 3: grouting3.jpg
Attachment 4: grouting4.png
8477   Tue Apr 23 16:17:45 2013 DenUpdatePEMseismometer isolation kit in place

 Quote: The carpenter shop finished the installation of the 3 granite bases.Rapid Set Cement All high strength non-shrink grout was used.  Compressive strength  3000 PSI at 1 hour and 9000 PSI at day 28 The janitor is still cleaning up after them at the south end. The  soft silicon gas kits are working well with the SS can.  Den is making  the adaptor plate drawing for the feedthrough.

To put everything in one place I add a final drawing of the base to this elog.

Next time we continue with wiring and putting temperature and pressure sensors inside the box. Connector support plate drawing is attached. We'll have sensors inside the kit with STS-2 or Trillium as their connector is small enough (19 pin vs 26 pin for Guralps) that we can put an additional 4 pin lemo connecor (2 pins for each sensor). I think EGG.0B.304.CLL is good for this application. Temperature and pressure sensor we can by from omega.

Attachment 1: Base.pdf.pdf
Attachment 2: ConnectorPlate.pdf
7153   Sat Aug 11 18:57:07 2012 DenUpdatePEMseismometer location

STS-2 - end of X arm

GUR 2 - isolation box

TRILLIUM - 1Y3 (DC power supply uses 1Y3 AC power, please do not close the door completely)

GUR 1 - end of Y arm

Now we have several "triangular seismic antennas". Different configurations can be chosen to compare the results.

7819   Thu Dec 13 01:49:53 2012 ranaUpdatePEMseismometers

 Quote: I've installed Guralp readout box back and it turned out that it does not work with voltage provided from the rack (+13.76 0 -14.94).  +/-12 voltage regulators inside the box convert it to -0.9 0 -12. I've connected the box to +/-15 DC voltage supply to measure seismic motion at the ETMY table. Readout box works fine with +/- 15. Seismic noise on the ETMY table measured to be a few times higher then on the floor in horizontal direction in the frequency range 50 - 200 Hz. Attached are compared spectrums of X, Y and Z motions.

Looking at the PEM BLRMS, I noticed that the GUR1Z channel had a much reduced microseism compared to the GUR1X. Looking at the BLRMS screens everything seems ON, although its a mess (too many filters in the banks, etc. - clean this up, PEM people).

Looking at the Z channel in DTT, I see that the Z spectra looks double high pass filtered below ~1 Hz.     Needs some attention in the daytime.

From Den and Ayaka's elog entry from Nov 29, its clear that this problem is there at that time. It seems that the seismometer was not even hooked up before then. Perhaps Tara returned the seismometer around Thanksgiving and then someone here hooked it up but neglected to log this work? If so, please make an elog now describing the installation of this sensor at the 40m and log any future work which takes place at the 40m lab even if you think it is inconsequential.

Attachment 1: a.pdf
7825   Thu Dec 13 21:21:34 2012 DenUpdatePEMseismometers

 Quote: Looking at the PEM BLRMS, I noticed that the GUR1Z channel had a much reduced microseism compared to the GUR1X. Looking at the BLRMS screens everything seems ON, although its a mess (too many filters in the banks, etc. - clean this up, PEM people).  Looking at the Z channel in DTT, I see that the Z spectra looks double high pass filtered below ~1 Hz.     Needs some attention in the daytime. From Den and Ayaka's elog entry from Nov 29, its clear that this problem is there at that time. It seems that the seismometer was not even hooked up before then. Perhaps Tara returned the seismometer around Thanksgiving and then someone here hooked it up but neglected to log this work? If so, please make an elog now describing the installation of this sensor at the 40m and log any future work which takes place at the 40m lab even if you think it is inconsequential.

Yesterday I wanted to recenter Guralps. I turned them off, understood that would be able to center them because we do not have power cable to Guralp box from Tara yet and turned them back on.

I've switched Guralp cables and spectrums are fine now.

Attachment 1: gur.pdf
Attachment 2: gur_fix.pdf
3037   Wed Jun 2 18:09:32 2010 steveUpdatePEMseismometers off of linoleum floor

Steve for Nancy,

Seismometer interface box ac power was turned off, Guralps disconnected and moved. Ranger locked, moved and released. Nancy will describe the rest soon.

3039   Wed Jun 2 21:21:43 2010 steveUpdatePEMseismometers off of linoleum floor

 Quote: Steve for Nancy, Seismometer interface box ac power was turned off, Guralps disconnected and moved. Ranger locked, moved and released. Nancy will describe the rest soon.

The flattened lead balls were checked for their heights by the calliper, and were all in the range of 9.50 to 9.70 mm.

The rechecking was done by using these balls between two aluminium plates and checking their levelling. When confirmed this, we proceeded to install the balls(no more balls :P ) in their place.

The Guralps were switched off by switching off the power supply to them. The ranger mass was clamped in order to be able to move it. This can be undone by rotating the transport screw counter-clockwise.

We installed the flattened lead ballsin the space made for them. The granite was then placed on it with the help of many other people in the lab.  It was lowered by hanging it on two straps held by people , and then placed in the space marked for it.

Did we then turn on the seismometers? Did we release the locking screw on the Ranger? What happened to Bat-Boy??? Since they make a good mystery I will choose to leave them out of my elog entry.

3047   Thu Jun 3 22:17:05 2010 ranaUpdatePEMseismometers off of linoleum floor

At ~2350 UTC on June 2, the seismometers were turned off. After the granite slab was repositioned with the new lead, the Ranger was turned on, but not the Guralps.

Now, after ~24 hours, I have put the Guralps onto the granite and turned them on. During this off time, the input channels should be ADC noise limited (or perhaps limited by the INA134 differential receiver chips inside of the Sander Liu AA chassis). The following plot shows that this noise level is ~0.8 uV/rHz and then rising like ~1/sqrt(f) below 5 Hz:

I checked the slab again by whacking it. It still rings with a Q of several, so I think we need to make the lead flatter. There should barely be any room between the granite and the linoleum.

UPDATE:

I guessed that it should be possible to make the slab-to-floor coupling better with flatter lead (Brian Lantz suggested to use lead sheets). So I removed my booties and jumped up and down on the granite several times. Because of my soft sole shoes, I was able to make an impulsive impact without shattering the granite. The effect of the stomping was pretty dramatic - the horizontal resonance frequency has gone up by a factor of 2. The red trace shows the new TF after the stomping:

And the resulting spectrum is here too. As you can see, there is no excess between the Ranger and the Guralps until ~50 Hz where the mechanical resonance in the short direction (non-MC dir) takes over.

So, the lesson for next time is to flatten the balls a little more. I leave it to Nancy to calculate the horizontal resonant frequencies of this lead/granite combo to see if it matches with our measurements.

3050   Fri Jun 4 23:52:57 2010 ranaUpdatePEMseismometers off of linoleum floor

For the huddle test, I have updated the code to divide the residual by sqrt(2) because of the assumption of equal noise from the 2 Guralps. We would have to multiply this trace by sqrt(2) to compare with the previous results.

Now the question is, how do I add a low noise ~50 mV offset to the front of the Guralp breakout box to test for the noise of the box?

2289   Wed Nov 18 01:12:15 2009 ranaUpdatePEMseismometers were not saturating during Halloween weekend
Attachment 1: Untitled.png
7254   Thu Aug 23 10:08:13 2012 SteveUpdatePEMseismometers?

 Quote: It seems as though there is something funny going on around ~1.5 Hz, starting a little over an hour ago. We see it in the BLRMS channels, the raw seismometer time series, as well as in various suspensions and LSC control signals.  It's also pretty easy to see on the camera views of all the spots (MC, arms, transmissions....AS is a little harder to tell since it's flashing, but it's there too). The plots I'm attaching are only for ~10min after the jump happened, but there has been no change in the BLRMS since it started.  Usually, we'd see an earthquake in all the channels, and even big ones ring down after a little while.  This is concentrated at a pretty narrow frequency (some of Den's plots for later have this peak), and it's not ringing down, so it's not clear what is going on. Here is a whole pile of plots.  Recall that the T-240 is plugged into the "STS_3" channels, and we don't have BLRMS for it, so you can look at the time series, but not any frequency specific stuff.

Atm1,  I'm not sure about the seismic data.   Baja earthquake magnitude 3.0 at  yesterday morning.Seismometers do not see them !

Atm2,  No posted seismic activity.  Someone is jump walking in the lab? Why are there time delays between the suspensions?

Attachment 1: bajaMag3.png
Attachment 2: seisvssus.png
13461   Sun Dec 3 05:25:59 2017 gautamConfigurationComputerssendmail installed on nodus

Pizza mail didn't go out last weekend - looking at logfile, it seems like the "sendmail" service was missing. I installed sendmail following the instructions here: https://tecadmin.net/install-sendmail-server-on-centos-rhel-server/

Except that to start the sendmail service, I used systemctl and not init.d. i.e. I ran systemctl start sendmail.service (as root). Test email to myself works. Let's see if it works this weekend. Of course this isn't so critical, more important are the maintenance emails that may need to go out (e.g. disk usage alert on chiara / N2 pressure check, which looks like nodus' responsibilities).

13462   Sun Dec 3 17:01:08 2017 KojiConfigurationComputerssendmail installed on nodus

An email has come at 5PM on Dec 3rd.

9578   Mon Jan 27 17:49:46 2014 ranaHowToComputer Scripts / Programssendmail started on nodus: fixing SwiftMail on Dokuwiki

Since the recent filesystem fracas, the new accounts could not be created on nodus / dokuwiki (for the controls workshop, for example).

I started sendmail on nodus using the command:   sudo /etc/init.d/sendmail start

and the SwiftMail plugin on there is now sending out the confirmation emails again. This will happen each time we reboot nodus, so let's replace it.

13539   Fri Jan 12 12:31:04 2018 gautamConfigurationComputerssendmail troubles on nodus

I'm having trouble getting the sendmail service going on nodus since the Christmas day power failure - for some reason, it seems like the mail server that sendmail uses to send out emails on nodus (mx1.caltech.iphmx.com, IP=68.232.148.132) is on a blacklist! Not sure how exactly to go about remedying this.

Running sudo systemctl status sendmail.service -l also shows a bunch of suspicious lines:

Jan 12 10:15:27 nodus.ligo.caltech.edu sendmail[6958]: STARTTLS=client, relay=cluster6a.us.messagelabs.com., version=TLSv1/SSLv3, verify=FAIL, cipher=DHE-RSA-AES256-GCM-SHA384, bits=256/256 Jan 12 10:15:45 nodus.ligo.caltech.edu sendmail[6958]: w0A7QThE032091: to=<umakant.rapol@iiserpune.ac.in>, ctladdr=<controls@nodus.ligo.caltech.edu> (1001/1001), delay=2+10:49:16, xdelay=00:00:39, mailer=esmtp, pri=5432408, relay=cluster6a.us.messagelabs.com. [216.82.251.230], dsn=4.0.0, stat=Deferred: 421 Service Temporarily Unavailable Jan 12 11:15:23 nodus.ligo.caltech.edu sendmail[10334]: STARTTLS=client, relay=cluster6a.us.messagelabs.com., version=TLSv1/SSLv3, verify=FAIL, cipher=DHE-RSA-AES256-GCM-SHA384, bits=256/256 Jan 12 11:15:31 nodus.ligo.caltech.edu sendmail[10334]: w0A7QThE032091: to=<umakant.rapol@iiserpune.ac.in>, ctladdr=<controls@nodus.ligo.caltech.edu> (1001/1001), delay=2+11:49:02, xdelay=00:00:27, mailer=esmtp, pri=5522408, relay=cluster6a.us.messagelabs.com. [216.82.251.230], dsn=4.0.0, stat=Deferred: 421 Service Temporarily Unavailable Jan 12 12:15:25 nodus.ligo.caltech.edu sendmail[13747]: STARTTLS=client, relay=cluster6a.us.messagelabs.com., version=TLSv1/SSLv3, verify=FAIL, cipher=DHE-RSA-AES256-GCM-SHA384, bits=256/256 Jan 12 12:15:42 nodus.ligo.caltech.edu sendmail[13747]: w0A7QThE032091: to=<umakant.rapol@iiserpune.ac.in>, ctladdr=<controls@nodus.ligo.caltech.edu> (1001/1001), delay=2+12:49:13, xdelay=00:00:33, mailer=esmtp, pri=5612408, relay=cluster6a.us.messagelabs.com. [216.82.251.230], dsn=4.0.0, stat=Deferred: 421 Service Temporarily Unavailable

Why is nodus attempting to email umakant.rapol@iiserpune.ac.in?

13540   Fri Jan 12 16:01:27 2018 KojiConfigurationComputerssendmail troubles on nodus

I personally don't like the idea of having sendmail (or something similar like postfix) on a personal server as it requires a lot of maintenance cost (like security update, configuration, etc). If we can use external mail service (like gmail) via gmail API on python, that would easy our worry, I thought.

13542   Fri Jan 12 18:22:09 2018 gautamConfigurationComputerssendmail troubles on nodus

Okay I will port awade's python mailer stuff for this purpose.

### gautam 14Jan2018 1730: Python mailer has been implemented: see here for the files. On shared drive, the files are at /opt/rtcds/caltech/c1/scripts/general/pizza/pythonMailer/

gautam 11Feb2018 1730: The python mailer had never once worked successfully in automatically sending the message. I realized this may be because I had put the script on the root user's crontab, but had setup the authentication keyring with the password for the mailer on the controls user. So I have now setup a controls user crontab, which for now just runs the pizza mailing. let's see if this works next Sunday...

 Quote: I personally don't like the idea of having sendmail (or something similar like postfix) on a personal server as it requires a lot of maintenance cost (like security update, configuration, etc). If we can use external mail service (like gmail) via gmail API on python, that would easy our worry, I thought.

13545   Sat Jan 13 02:36:51 2018 ranaConfigurationComputerssendmail troubles on nodus

I think sendmail is required on nodus since that's how the dokuwiki works. That's why the dokuwiki was trying to send an email to Umakant.

13546   Sat Jan 13 03:20:55 2018 KojiConfigurationComputerssendmail troubles on nodus

I know it, and I don't like it. DokuWiki seems to allow us to use an external server for notification emails. That would be the way to go.

4851   Tue Jun 21 23:29:41 2011 kiwamuUpdateLSCsensing matrix measurement

I am now measuring the sensing matrix in the DRMI configuration.

A goal of tonight is to measure the sensing matrix as a test of the script.

The result will be updated later.

4857   Wed Jun 22 17:42:03 2011 kiwamuUpdateLSCsensing matrix measurement

The sensing matrix was measured in the DRMI configuration for the first time.

The measurement was done by an automatic script and the realtime LOCKIN module built in the c1lsc model.

The resultant matrix is still too primitive, so I will do some further analysis.

(Measurement of sensing matrix)

The quantities we want to measure are the transfer functions (TFs) from displacement (or change in optical phase) of each DOF to sensors in unit of [counts/m].

So essentially the measurement I did is the same as the usual TF measurement. The difference is that this measurement only takes TFs at a certain frequency, in this case 283 Hz.

The measurement goes in the following order :

(1) Lock DRMI

(2) Shake an optic of interest longitudinally with an amplitude of 1000 counts at 283.103 Hz, where no prominent noise structures are present in any spectra of the sensor signals.

(3) Put a notch filter at the same frequency of 283.103 Hz in each DOF (MICH, PRC and SRC) to avoid unwanted suppression due to the control loops.

(This technique is essentially the same as this one, but this time the control loops are shut off only at a specific frequency )

The notch filter I put has a depth of 60 dB and Q of 20. The filter eats the phase of ~10 deg at 200 Hz, which still allow servos to run with a high UGF up to 200Hz.

(4) Take the output signal from a signal port of interest (i.e. REFL11_I, etc.,) and then put it into the realtime LOCKIN module.

(5) Measure the resultant I and Q signals coming out from the LOCKIN module.

(6) Repeat the procedure from (2) through (5) for each optic and sensor.

(Results)

Again, the resultant sensing matrix is still primitive, for example the optic-basis should be converted into the DOF basis.

The values listed in the matrix below is the absolute values obtained by operation of sqrt( I^2 + Q^2) plus the polarity according to the output from I and Q of LOCKIN.

Therefore they still contain the actuator response, which is not desired. i will calibrate them into [counts/m] later by using the calibration factor of the actuator responses.

All the raw data showed the relative phase between I and Q either ~ 127 deg or ~ -53 deg.

In my definition, the one has 127 deg is plus polarity and the one has -53 deg is minus polarity.

Technically speaking the polarity depends on the polarity of the actuator and also the direction of the actuator against the DOFs.

Without any excitation the absolute values fluctuated at about 10-4 - 10-5, so the excitation amplitude was big enough to observe the sensing matrix.

Though, I still need to estimate the statistical errors to make sure the SNR is reasonably big.

Fig.1 Measured sensing matrix from optic to sensors.

(Things to be done)

- convert the optic-basis (i.e. BS, ITMs, PRM and SRM) to the DOF-basis (i.e. MICH, PRC and SRC) so that the matrix is understandable from point of view of the interferometer control.

- estimate the optimum demodulation phase for each DOF at each sensor port.

- add some statistical flavors (e.g. error estimations and so on.)

- edit the script such that it will keep watching the ADC overflows and the coherence to make sure the measurement goes well.

- add some more signal ports (e.g. REFL55, POY55 and etc.)

- compare with an Optickle model

 Quote from #4851 The result will be updated later.

4899   Tue Jun 28 15:20:08 2011 kiwamuUpdateLSCsensing matrix measurement in PRMI configuration

Here is the result of the measurement of the sensing matrix in the PRMI configuration.

If we believe the resultant matrix, it is somewhat different from what we expected from a finesse simulation (summary of simulated sensing matrix).

(Motivation)

As a part of the DRMI test plan, we wanted to check the sensing matrices and consequently diagonalize the LSC input matrix.

The matrix of the DRMI configuration has been measured (#4857), but it was a bit too complicated as a start point.

So first in order to make sure we are doing a right measurement, we moved onto a simpler configuration, that is PRMI.

(measurement)

The technique I used was the same as before (#4857) except for the fact that SRM wasn't included this time.

- PRC was locked to the carrier resonant point. The UGF of MICH and PRC were ~ 110 Hz and 200 Hz respectively.

- Longitudinally shook BS, ITMs and PRM at 283.103 Hz with an amplitude of 1000 counts using the LOCKIN oscillator in C1LSC.

- Took the I and Q phase signals from the LOCKIN outputs.

The table below is the raw data obtained from this measurement :

(Conversion of matrix)

With the matrix shown above, we should be able to obtain the sensing matrix which gives the relation between displacements in each DOF to each signal port.

The measured matrix connects two vectors, that is,

 (signal port vector) = [Measured raw matrix] (SUS actuation vector),   -- eq.(1)

where

(signal port vector) = (AS55_I, AS55_Q, REFL11_I, REFL11_Q)T   in unit of [counts],

    (SUS actuation vector) = (BS, ITMX, ITMY, PRM)T   in units of [counts].

Now we break the SUS actuation vector into two components,

  (SUS actuation vector [counts])  = (actuator response matrix [m/counts])-1 * (MICH, PRM [m] )^T   -- eq.(2)

where

(actuator response matrix) =  2.05x10-13 * ( [1   ,  0.217, -0.216,   0  ],

                                                 [ 0.5,  0.109 -0.108, 0.862]  )  in unit of [m/counts]

These values are coming from the actuator calibration measurement.

In the bracket all the values are normalized such that BS has a response of 1 for MICH actuation.

Combining eq.(1) and (2) gives,

    (signal port vector) = (measured raw matrix) * (actuator response matrix)-1 * (MICH, PRM)T

And now we define the sensing matrix by

(sensing matrix) = (measured raw matrix) * (actuator response matrix)-1

The sensing matrix must be 4x2 matrix.

For convenience I then converted the I and Q signals of each port into the absolute value and phase.

       ABS = sqrt((AAA_I)2 +(AAA_Q)2 ),

       PHASE = atan (AAA_Q / AAA_I),

where AAA is either AS55 or REFL11.

(Resultant matrix)

The table below is the resultant sensing matrix.

ABS represents the strength of the signals in unit of [cnts/m], and PHASE represents the demodulation phases in [deg].

There are several things which I noticed :

- The demodulation phase of MICH=>AS55 and PRC=>REFL11 are close to 0 or 180 deg as we expected.

This is a good sign that the measurement is not something crazy.

- AS55 contains a big contribution from PRC with a separation angle of 152 deg in the demodulation phase.

In AS55 the signal levels of MICH and PRC were the same order of magnitude but PRC is bigger by a factor of ~4.

However the finesse simulation (see wiki page) shows a different separation angle of 57 deg and MICH is bigger by factor of ~6.

- REFL11 is dominated by PRC. The PRC signal is bigger than MICH by a factor of ~100, which agrees with the finesse simulation.

However the separation angle between PRC and MICH are different. The measurement said only 19 deg, but the simulation said ~ 90 deg.

- Woops, I forgot to calibrate the outputs from the LOCKIN module.

The whole values must be off by a certain factor due to the lack of the calibration , but fortunately it doesn't change the demodulation phases.

 Quote from #4884 I was able to measure the sensing matrix in the PRMI configuration. The results will be posted later.

4910   Wed Jun 29 12:20:53 2011 kiwamuUpdateLSCsensing matrix measurement in PRMI configuration

Of course I made a mistake in my calculation of the sensing matrix. I will figure out which point I mistook.

The MICH signal must have the demodulation phase of around 90 deg in AS55

because we had adjusted the demodulation phase such that the MICH signal mostly appears on AS55_Q.

 Quote: Here is the result of the measurement of the sensing matrix in the PRMI configuration.

6281   Wed Feb 15 05:29:22 2012 kiwamuUpdateLSCsensing matrix of PRMI

I have measured the sensing matrix of PRMI.

It seems that the MICH signal in the 3f ports (REFL33 and REFL165) were quite tiny, and because of that it is very tough to use them for the actual MICH control.

The data is coming soon.

6283   Wed Feb 15 17:15:33 2012 kiwamuUpdateLSCsensing matrix of PRMI

I think I have told a lie in the last meeting -- the measured sensing matrix doesn't look similar to what Optickle predicts.

Smells like something is very wrong.

Measured sensing matrix

The measured matrix are shown in the diagram below.
The lengths of arrows corresponds to the signal strength in unit of V/m. The radial axis in in log scale.
The angle of arrows corresponds to their best demodulation phases.

Some obvious things:

•  REFL11 : The separation angle between MICH and PRCL is narrow and it is far from the ideal 90 degree. This doesn't agree with the simulation.
•  REFL33:  The MICH and PRCL signals are almost degenerated in their demodulation phase.
•  REFL55 :  It shows non-90 degree separation. This doesn't agree with the simulation.
•  REFL165 : The separation is close to 90 degree, but the signals are small. And I am not sure if the MICH signal is real or just noise.
•  AS55 : Somehow it shows a nice 90 degree separation, but this result doesn't agree with the simulation.

Expected sensing matrix from a simulation

For a comparison here is a result from an Optickle simulation.
This time the radial unit is W/m instead of V/m, but they are qualitatively the same unit.
The radial axis is in log, so when it says 2, it means 10^2 [W/m].

Simulation setup:
l_PRC  = 6.760 (see #4064)
l_asy  = 0.0364  (see #4821)
loss per optic = 50 ppm

Measurement

•  Locked PRMI with the carrier anti-resonating in PRCL.
•  Adjusted the control gains for both the MICH and PRCL control to have UGFs at ~ 100 Hz.
•  Put a 30 dB notch filter  in each control servo at 283.1 Hz where an excitation signal will be.
•  Excited PRCL and MICH at different time via the realtime lockng in the LSC front end. The amplitude is 1000 counts and the frequency is at 238.1 Hz.
• For the MICH excitation, I have coherently and differentially excited ITMs
•  Used DTT to take a transfer function (transfer coefficients at 283.1 Hz) from the lockin oscillator to each LSC demodulated signal.
• Including AS55I/Q, REFL11I/Q, REFL33I/Q, REFL55I/Q and REFL165I/Q.
•  Calibrated the obtained transfer functions from unit of counts/counts to V/m using the actuator response (#5637)

 Quote from #6281 I have measured the sensing matrix of PRMI. It seems that the MICH signal in the 3f ports (REFL33 and REFL165) were quite tiny, and because of that it is very tough to use them for the actual MICH control. The data is coming soon.

6287   Thu Feb 16 07:38:24 2012 KojiUpdateLSCsensing matrix of PRMI

So why don't you use AS55I and Q for the control of PRMI???

6289   Thu Feb 16 13:12:30 2012 ranaUpdateLSCsensing matrix of PRMI

 Quote: I think I have told a lie in the last meeting -- the measured sensing matrix doesn't look similar to what Optickle predicts. Smells like something is very wrong.

Those Radar plots are awesome. Even more awesome would be if they were in units of W/m (so that it can be directly compared with Optickle) and so that the numbers are useful even 1 year from now. Otherwise, we will lose the RF transimpedance information and thereby lose everything.

Also, please post the provenance of the counts->V calibration.

6293   Fri Feb 17 04:45:48 2012 kiwamuUpdateLSCsensing matrix of PRMI

I locked the PRMI with the AS55I and Q combination.

It seems the glitche rate decreased,

but I am not 100 % sure because the rest of the demod signals (i.e. REFL11 and etc) were showing relatively big signals (noise ?), which may cover the glitches.

Also the optical gain of PRCL at AS55I doesn't agree with my expectation based on the obtained sensing matrix (#6283).

It looks too low and lower than the measured sensing matrix by a factor of 50 or so.

I will continue working on this configuration tomorrow and then move on to the SRMI locking as a part of the glitch hunting activity.

 Quote from #6287 So why don't you use AS55I and Q for the control of PRMI???

4427   Wed Mar 23 05:11:08 2011 kiwamuUpdateGreen Lockingservo handig off

Succeeded in handing off the servo from the green to the red.

(noise performance)

This time we found that the fluctuation in the IR signals became lesser as the gain of the ALS servo increased.

Therefore I increased the UGF from 40 Hz to 180 Hz to have less noise in the IR PDH signal.

Here is a preliminary plot for today's noise spectra.

The blue curve is the ALS in-loop spectrum, that corresponds to the beat fluctuation.

The red curve is an out-of-loop spectrum taken by measuring the IR PDH signal.

Since the UGF is at about 180 Hz the rms is integrated from 200 Hz.

The residual displacement noise in the IR PDH signal is now 1.2 kHz in rms.

I am going to analyze this residual noise by comparing with the differential noise that I took yesterday (see the last entry ).

4428   Wed Mar 23 08:50:36 2011 AidanUpdateGreen Lockingservo handig off

Nicely done!

 Quote: Succeeded in handing off the servo from the green to the red.

Attachment 1: green-to-red.jpg
9151   Sun Sep 22 21:28:53 2013 ranaUpdateSUSset OL T RAMP values (they are not visible on the OL screens)

controls@rosalba:/opt/rtcds/caltech/c1/scripts/SUS 0\$ ./setOLtramps
Old : C1:SUS-ETMX_OLPIT_TRAMP        0
New : C1:SUS-ETMX_OLPIT_TRAMP        2
Old : C1:SUS-ETMX_OLYAW_TRAMP        0
New : C1:SUS-ETMX_OLYAW_TRAMP        2
Old : C1:SUS-ETMY_OLPIT_TRAMP        2
New : C1:SUS-ETMY_OLPIT_TRAMP        2
Old : C1:SUS-ETMY_OLYAW_TRAMP        2
New : C1:SUS-ETMY_OLYAW_TRAMP        2
Old : C1:SUS-ITMX_OLPIT_TRAMP        0
New : C1:SUS-ITMX_OLPIT_TRAMP        2
Old : C1:SUS-ITMX_OLYAW_TRAMP        0
New : C1:SUS-ITMX_OLYAW_TRAMP        2
Old : C1:SUS-ITMY_OLPIT_TRAMP        0
New : C1:SUS-ITMY_OLPIT_TRAMP        2
Old : C1:SUS-ITMY_OLYAW_TRAMP        0
New : C1:SUS-ITMY_OLYAW_TRAMP        2
Old : C1:SUS-BS_OLPIT_TRAMP          0
New : C1:SUS-BS_OLPIT_TRAMP          2
Old : C1:SUS-BS_OLYAW_TRAMP          0
New : C1:SUS-BS_OLYAW_TRAMP          2
Old : C1:SUS-PRM_OLPIT_TRAMP         0
New : C1:SUS-PRM_OLPIT_TRAMP         2
Old : C1:SUS-PRM_OLYAW_TRAMP         0
New : C1:SUS-PRM_OLYAW_TRAMP         2
Old : C1:SUS-SRM_OLPIT_TRAMP         0
New : C1:SUS-SRM_OLPIT_TRAMP         2
Old : C1:SUS-SRM_OLYAW_TRAMP         0
New : C1:SUS-SRM_OLYAW_TRAMP         2

Done setting TRAMPs

8809   Tue Jul 9 11:37:37 2013 gautamUpdateCDSset up for testing DAC Interface-board pin outs

The bank marked channel 9-16 is free, but the connector is a 40 pin IDC and I need to know the exact pin-out configuration before I can set about making the custom ribbon cable that will send the control signals from the DAC card to the PZT driver board.

The DAC interface board on rack 1Y4 seems to be one of the first versions of this board, and has no DCC number anywhere on it. Identical modules on other racks have the DCC number D080303, but this document does not exist and there does not seem to be any additional documentation anywhere. The best thing I could find was the circuit diagram for the ADL General Standards 16-bit DAC Adapter Board, which has what looks like the pin-out for the 68 pin SCSI connector on the DAC Interface board. Koji gave me an unused board with the same part number (D080303) and I used a multimeter and continuity checking to make a map between DAC channels, and the 40 pin IDC connector on the board, but this needs to be verified (I don't even know if what is sitting inside the box on 1Y4 is the same D080303 board).

Jenne suggested making a break-out cable to verify the pin-outs, which I did with a 40-pin IDC connector and a bit of ribbon wire. The other end of the ribbon wire has been stripped so that we can use some clip-on probes and an oscilloscope to verify the pin-outs by sending a signal to DAC channels 9 through 16 one at a time. On the software side, Jenne did the following:

• Restarted the mx_stream on c1iscey  (unrelated to this work)
• Model compiled and installed

We have not restarted c1scy yet as Annalisa is working on some Y-arm stuff right now. We will restart c1scy and use awggui to perform the test once she is done.

Pink edits by JCD

8811   Tue Jul 9 12:01:20 2013 gautamUpdateCDSset up for testing DAC Interface-board pin outs

Jenne just rebooted c1scy and daqd on the framebuilder. We will do the actual test after lunch.

3407   Thu Aug 12 11:59:31 2010 kiwamuHowToCDSset up ntp daemom

When I was working on a new front end machine c1sus, I found that make command didn't run and gave the following message.

"make:warning:clock skew detected.Your build may be incomplete"

This was caused by a clock difference between the nfs (nodus) and the terminal machine (c1sus).

I had to set up ntp daemon to synchronize them. Here is a procedure to set up it

(how to)

ssh c1sus

- enable the ntp daemon

sudo ntsysv

- configure the ntpd

 vi (emacs)  /etc/ntp.conf

- below is the contents I wrote on ntp.conf

server 192.168.113.200  minpoll 4 maxpoll 4 iburst

      driftfile /var/lib/ntp/drift

- let the daemon run
 sudo service ntpd start
- check it if it's running
ntpq -p
1529   Tue Apr 28 16:36:24 2009 robHowToLockingsetting the RF CARM demod phase

To set the demod phase for RF CARM, sensed at REFL2 (REFL 166I), it suffices to set the demod phase for REFL2 to be the optimal phase for controlling SRCL in a no-arm state.

Attachment 1: CARM_phases_REFL.pdf
Attachment 2: SRCL_phases_REFL.pdf
1530   Tue Apr 28 17:51:13 2009 robHowToLockingsetting the RF CARM demod phase

 Quote: To set the demod phase for RF CARM, sensed at REFL2 (REFL 166I), it suffices to set the demod phase for REFL2 to be the optimal phase for controlling SRCL in a no-arm state.

For POX33, the ideal phase for single arm locking does not yield a zero-offset CARM signal.  So the offset needs to be manipulated digitally.

Attachment 1: XARM_phases_POX.pdf
Attachment 2: CARM_phases_POX.pdf
3630   Thu Sep 30 18:51:50 2010 yutaUpdateComputerssetting up aldabella and mariabella

(Kiwamu, Yuta)

Background:
We wanted to make aldabella and mariabella know how to work.

What we did:

1. Added 2 lines to /etc/rc.local
 /sbin/modprobe ndiswrapper  sleep 10  mount linux1:/home/cds/ /cvs/cds

2. Edited ~/.cshrc
 source /cvs/cds/caltech/cshrc.40m

Result:
Working environment is set to aldabella and mariabella. They have their access to the main system, linux1, now.

Note:
fstab doesn't work for aldabella and mariabella because the mount should be done after ndiswrapper loads.

13409   Mon Nov 6 09:09:43 2017 SteveUpdateVACsetting up new TP2 turbo

Our new Agilent Technology TwisTorr 84FS AG rack controller ( English Manual pages 195-297 )  RS232/485, product number X3508-64001, sn IT1737C383

This controller, turbo and it's drypump needs to be set up into our existing vacuum system. The intake valve of this turbo (V4) has to have a hardwired interlock that closes V4 when rotation speed is less than 20% of preset RPM speed.

The unit has an analoge 10Vdc output that is proportional to rotation speed. This can be used with a comperator to direct the interlock or there may be set software option in the controller to close the valve if the turbo slows down more than 20%

The last Upgrade of the 40m Vacuum System  1/2/2000 discribes our  vauum system  LIGO-T000054-00-R

Here the LabView / Metrabus controls were replaced by VME processor and  an Epic interface

We do not have schematics of the hardware wiring.

We need help with this.

3892   Thu Nov 11 05:56:04 2010 yutaSummaryIOOsetting up temporary oplev for coil balancing of MCs

(Suresh, Yuta)

Background:
Previous A2L measurement is based on the assumption that actuator efficiencies are identical for all 4 coils.
We thought that the unbelievable "tilt" may be caused by imbalance of the coils.

Method:
1. Setup an optical lever.
2. Dither the optic by one coil and demodulate oplev outputs(OL_PIT or OL_YAW) in that frequency.
3. Compare the demodulated amplitude. Ideally, the amplitude is proportional to the coil actuation efficiency.

What we did:
[MC2]
MC2 is the least important, but the easiest.
1. Placed a red laser pointer at MC2 trans table. During the installation, I moved the mirror just before QPD.
2. Made a python script that measures coil actuation efficiency using the above method. I set the driving frequency to 20Hz.
It is /cvs/cds/caltech/users/yuta/scripts/actuatorefficiency.py.
The measurement result is as follows. Errors are estimated from the repeated measurement. (Attachment #1)

MC2_ULCOIL 1
MC2_URCOIL 0.953 ± 0.005
MC2_LRCOIL 1.011 ± 0.001
MC2_LLCOIL 0.939 ± 0.006

[MC1]
For MC1, we can use the main laser and WFS1 QPD as an oplev.
But we only have slow channels for QPD DC outputs(C1:IOO_WFS1_SEG#_DC).
So, we intentionally induce RF AM by EOM(see Kiwamu's elog #3888) and use demodulated RF outputs of the WFS1 QPD(C1:IOO_WFS1_I/Q#) to see the displacement.
1. Replaced HR mirror in the MCREFL path at AP table to BS so that we can use WFS1.(see Koji's elog #3878)
The one we had before was labeled 10% pick-off, but it was actually an 1% pick-off.
2. Checked LO going into WFS1 demodulator board(D980233 at 1X2).
power: 6.4dBm, freq: 29.485MHz
3. Turned on the hi-voltage(+100V) power supply going into the demodulator boards.
4. Noticed that no signal is coming into c1ioo fast channels.
It was because they were not connected to fast ADC board. We have to make a cable and put it in.

[MC3]
Is there any place to place an oplev?

Plan:
- prepare c1ioo channels and connections
- I think we'd better start A2L again than do oplev and coil balancing.

Attachment 1: MC2coils.png
3771   Sun Oct 24 18:06:35 2010 kiwamuSummaryLockingsetup for green beat

(notes on signal level)

The signal level of the observed peak was -48dBm.

However I was expecting it is like -28dBm with some ideal assumptions.

There may be a 20dB unknown loss which sounds big to me.

The expectation was calculated by using the following simple math.

SIGNAL = A x Z x G_RF x sqrt(P1 / 2) x sqrt (P2 / 2)

where A is the responsibility of the PD and Z is the trans impedance gain. G_RF is a gain of the RF amplifier.

The laser powers of green beams, P1 and P2, are divided by 2 due to a beam splitter.

I was assuming the parameters are like:

A = 0.39 [A/W]   (assuming 90% quantum efficiency at 532nm)

Z = 240 [V/A]

P1 = 17 uW  (measured by Newport power meter)

P2 = 30 uW (measured by Newport power meter)

G_RF = 23 dB

3774   Mon Oct 25 02:14:38 2010 KojiSummaryLockingsetup for green beat

- What is the actual photocurrent for the beam1 and beam2? We don't care how much power do you have before the BS, but care how much current do you have on the PD.

- How much is the visibility? There is mismatching of the beams. i.e. The beam diameter looked quite different. Also the beams are not TEM00 but have fringes probably comes from the TT mirrors. You maybe able to measure the visibility by the DC output, making the beat freq go through df=0 slowly.

- What is the measured gain of the RF amp? Does it include the voltage division by the output/input impedance?

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

The signal level of the observed peak was -48dBm.

However I was expecting it is like -28dBm with some ideal assumptions.

There may be a 20dB unknown loss which sounds big to me.

I was assuming the parameters are like:

A = 0.39 [A/W]   (assuming 90% quantum efficiency at 532nm)

Z = 240 [V/A]

P1 = 17 uW  (measured by Newport power meter)

P2 = 30 uW (measured by Newport power meter)

G_RF = 23 dB

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