Chris, Patrick I am going to turn the CW injections back on at H1. We are currently in single-IFO mode right now. And since this is the first time we are going to turn these back on, as a precaution I will ask Patrick (the operator on shift) to turn the intent mode off. The intent mode should only be off for a couple minutes at most. I will make an aLog entry when this work is done and the intent mode is back on. To do this we will: * Turn the intent mode off *Turn off the output of the continuous injection filterbankMore specifically turn off INJ_CW and INJ_HARDWARE. There is a startup transient in INJ_HARDWARE that we do not want to enter into the ESD * log into h1hwinj1/ on a work station browser * start psinject using the monit web interface * After a short time (a few seconds) turn on the output of the continuous injection filterbank so we don't inject the startup transient * Turn the intent mode back on
TJ, Josh, Andy, Joe
We used the ~18 hours of low noise data on October 12th to do a systematic check for DAC calibration glitches in the suspensions and found no clear evidence of any glitches due to calibration coupling into DARM. This check looks at crossings of 0 and +/- 2^16 for all SUS MASTER_OUT channels being sent to the DAC.
There were a few channels that showed zero or 2^16 crossings in coincidence with glitches in DARM, but these seem to be due to large glitches in the DARM loop driving the DAC output through 2^16 rather than the DAC output crossing through 2^16 and causing glitches.
We think some zero-crossings in PR3 might be coupling noticeably into PRCL, but we're still looking into this. The NOISEMON channel for PR3 M3 seems like it might be in need of a tune-up, it doesn't seem consistent with what we're seeing from other NOISEMONs.
A summary of our findings is stored at the following wiki: https://wiki.ligo.org/viewauth/DetChar/ER8DACglitchHveto
TITLE: 10/17 [DAY Shift]: 15:00-23:00 UTC (08:00-16:00 PDT), all times posted in UTC STATE Of H1: Observing @ ~ 78 MPc. OUTGOING OPERATOR: Nutsinee QUICK SUMMARY: From the cameras the lights are off in the LVEA, PSL enclosure, end X, end Y and mid X. I can not tell if they are off at mid Y. Seismic in 0.03 - 0.1 Hz band has just recovered from an earthquake and is around .015 um/s. Seismic in 0.1 - 0.3 Hz band is around .07 um/s. Winds are less than 10 mph. Company on site blowing out sprinklers.
TITLE: "10/17 [OWL Shift]: 07:00-15:00UTC (00:00-08:00 PDT), all times posted in UTC"
STATE Of H1: Observing at ~80 Mpc. IFO has been locked for 26 hours.
SUPPORT:
SHIFT SUMMARY: Nothing exciting until a 6.0M earthquake in Argentina (the R-wave arrive time was 05:19:26 PDT). LLO has been down for ~3 hours. The seismic activity in the earthquake band has come back to nominal. Low wind through out the night.
INCOMING OPERATOR: Patrick
ACTIVITY LOG:
14:50 Patrick's here early. He let a contractor through the gate (sprinkler blownout).
The range seems to have increased slightly during the past 12 hours which seems to correspond to a decrease in seismic activity in 1-3Hz band. Low wind. Nominal seismic activity in the eq band and microseism.
J. Kissel Inspired by several people looking at time-series and RMS of DARM that includes sub-10 [Hz] content (e.g. LHO aLOG 22513), I update my information on how well I think we can get the low frequency DARM displacement "right" below 10 [Hz] in the frequency domain by modifying H1:CAL-DELTAL_EXTERNAL_DQ in post-processing (originally posted in LHO aLOG 18248). The method for calibrating the CAL-DELTAL_EXTERNAL_DQ DARM channel and getting it "right" below 10 [Hz]: (1) undo the 5 zeros at 1 [Hz], 5 poles at 100 [Hz] whitening DAQ filter LHO aLOG 16702 as one would normally do for this channel at all frequencies. (2) compensate for the systematic error in CAL-CS from the rest of the low-frequency digital UIM/L1 LOCK L filter (FM1 "0.01:0", a pole at 0 [Hz], and a zero at 0.01 [Hz]) that we don't replicate in the CAL-CS actuation path because of numerical precision noise. (Originally discussed in LHO aLOG 17528) That means, in DTT, one should apply the following calibration filter: Gain: 0.01 Poles: 1,1,1,1,1, 0 Zeros: 100,100,100,100,100, 0.01 where the gain of (exactly) 0.01 is to normalize the z:p = (0.01 : 0) filter necessary for getting the actuation at low frequencies correct in step (2) -- i.e. 2*pi*[0.01] / 2*pi = 0.01. (Don't ask me why one needs to normalize the z:p = 0.01:0 filter but not the 100^5:1^5 filter, cause I don't know.) Details and Explanations and Caveats: ------------------------------------ All calibration below 10 [Hz] still should be treated with some skepticism, because - we have little-to-no precision measurements of the scale factor, DARM OLGTF frequency dependence, and/or TST/UIM cross-over frequency in this band (and we don't plan on making any). - the online CAL-CS calibration does not compensate for any very low-frequency global control, a.k.a. "tidal correction." The "calibrations" of each end's servos that are in place claim the EPICs gains for the UGF are in [Hz] (as measured by the Green PDH), but I know these calibrations were not at all carefully done (in the "probably within a factor of 2" ballpark). I compare against similarly "well" calibrated instrumentation in the attachment for comparison. Of course, there are lots of things going on with each of these instruments that makes this naive, "below the SUS resonances, DARM should be moving with the ground" comparison, including but not limited to - tilt is always confusing the issue below ~0.1 [Hz] for the interial sensors I show, - I don't show the ITMs, - there are many more mechanical DOFs of many more SUS than just the ETMs contributing to DARM at "mid" frequencies (between 0.1 and 5 [Hz]). - gain peaking and sensor noise pollution from from all of the mid-frequency ASC loops. - Angle to length coupling - The GS13s that inform the ISIWIT channels are in-loop, and limited by sensor noise above ~0.5 [Hz] - gain peaking from HEPI and ISI loops - relative motion between the HAMs and BSCs on the readout chain of DARM which makes the comparison difficult to say who's "right" with out a LOT more measurements and cross-checks. In summary, I could say it's "within a factor of two," because I think we've done everything right, and that's what we always say when we first guess at how well we've done with these sorts of "worked on it carefully for a day, but no one else has looked at it, and it's the first time trying," things, but I have no measured proof to bound the uncertainty quantitatively. -------------- Note because we've needed to do a better job at low-frequency to get the 10 [Hz] motion right, the additional corrections one must make to CAL-CS are at lower frequency than they used to be in ER7. Also note, this should be the same correction for H1:GDS-CALIB_STRAIN, because former is produced by the latter, and there are no known additional corrections / systematics that aren't already covered by the front-end's production of H1:CAL-DELTAL_EXTERNAL. -------------- Why (2) works: Remember that DELTAL_EXTERNAL is the sum of the calibrated DARM_ERR and DARM_CTRL channels, DELTAL_EXTERNAL = (1 / C) * DARM_ERR + A * DARM_CTRL where C is the sensing function (i.e. the IFO's "test mass DARM displacement sensor" calibration) and A is the actuation function (i.e. the ETMY transfer function). A dominates this sum below the DARM UGF at ~40 [Hz]. As such, well below 40 [Hz], DELTAL_EXTERNAL ~ A * DARM_CTRL. Since we're using hierarchical feed back to ETMY, where the UIM/TST or L1/L3 cross-over frequency is ~1 [Hz], then well below *that*, DELTAL_EXTERNAL ~ A_{uim} * DARM_CTRL, i.e. the total calibration for DELTAL_EXTERNAL "well" below 1 [Hz] is dominated by how accurately we reproduce / calibrate / model the UIM actuation path. Since the UIM digital filters we've intentionally left out in CAL-CS have frequency content below ~0.01 [Hz], they're simply "missing" from the calibration of DELTAL_EXTERNAL, and we can, offline, just multiply all of DARM by these filters, and get the "right" answer. ---------------
TITLE: Oct 17 OWL Shift 07:00-15:00UTC (00:00-08:00 PDT), all times posted in UTC
STATE Of H1: Observing
OUTGOING OPERATOR: Ed
QUICK SUMMARY: The ifo has been locking 18.5 hours. Wind below 5mph. Microseism reads 10^-1 um/s. Nominal seismic activity in EQ band (10^-2 um/s).
TITLE: Oct 16 EVE Shift 23:00-07:00UTC (04:00-00:00 PDT), all times posted in UTC
STATE Of H1: Observing
LOCK DURATION: Entire Shift ~80Mpc
SUPPORT: Jeff K
INCOMING OPERATOR: Nutsinee
Activity log:
23:29 Gerardo to MY for leak hunting activity
00:39 Gerardo left MY
Shift Summary:
IFO locked Entire shift. Wind and Sei calm.
SUS E_T_M_Y saturating (Oct 17 01:43:56 UTC)
SUS E_T_M_Y saturating (Oct 17 02:36:23 UTC)
SUS E_T_M_Y saturating (Oct 17 04:04:08 UTC)
SUS E_T_M_Y saturating (Oct 17 04:16:38 UTC)
SUS E_T_M_Y saturating (Oct 17 05:30:14 UTC)
SUS E_T_M_Y saturating (Oct 17 05:54:05 UTC)
Handing of to Nutsinee
Mid-Shift Summary:
No news is good news. Winds calm, EQ/µSei c glitches. Humming along at ~73Mpc.
We're still having operators run A2L before going to Observe or when leaving Observe (e.g. for maintenence), so there's more data to come, but I wanted to post what we do have, so that we can compare with LLO's aLog 21712.
The 2 plots are the same data: The first uses the same axis limits as the LLO plot, while the second is zoomed in by a factor of 5.
It certainly looks like we aren't moving nearly as much as LLO is.
Note that the values for both LLO and LHO are missing a coupling factor of L2P->L3L, which will change the absolute value of the spot position displacements. However, since we're both wrong by the same factor, our plots are still comparable. See aLog 22096 (the final comment in the linked thread) for details on the factor that we still need to include.
Today I went through all of the A2L data that has been collected so far, and pulled out for analysis all of the runs for each optic that had acceptable data. Here, I'm defining "acceptable" as data sets that had reasonable linear fits, as displayed in the auto-generated figures.
In particular, for almost all of the ETMY data sets, there is one data point that is very, very far from the others, with large error bars. I'm not sure yet why we seem to have so much trouble collecting data for ETMY. I've emailed Marie at LLO to see if they have similar symptoms.
For all of the times that we have taken measurements, I also checked whether the IFO had been on for more than 30 minutes or not. In both plots below, the cold blue data points are times when the IFO had been at Nominal Low Noise for less than 30 minutes prior to the measurement, while the hot pink data points are times when the IFO had been at Nominal Low Noise for at least 30 minutes.
The first plot is all of the data points that I accepted, plotted versus time. This is perhaps somewhat confusing, but each of the y-axes are centered about the mean spot position for that optic and degree of freedom, plus or minus 3 mm. So, each y-axis has a range of 6mm, although they're all centered around different values.
For the second plot, I find all the times that I have both acceptable pitch and yaw measurements, and plot the spots on a grid representing the face of the optic. Note that since I had zero acceptable ETMY Yaw data points, nothing is plotted for ETMY at all.
Interestingly, the ITM spots seem fairly consistent, regardless of how long the interferometer has been on, while the ETMX spots have a pretty clear trend of moving as the IFO heats up. None of our spots are moving more than +- 1.5 mm or so, so we are quite consistent.
TITLE: 10/16 [Day Shift]: 1500-23:00UTC
STATE Of H1: Observing at ~80 Mpc for the past 10 hours.
SUPPORT: Smaller than normal control room crowd
SHIFT SUMMARY: Locked the whole shift, Nutsinee clearly got all the pain today
ACTIVITY LOG:
16:30 Chris Joe to X arm for beam tube work
17:00 Gerardo to MY leak checking
19:00 Gerardo back
20:00 Joe, Chris back
TITLE: Oct 16 EVE Shift 23:00-07:00UTC (16:00-00:00 PDT), all times posted in UTC
STATE Of H1: Observing
OUTGOING OPERATOR: Jim
QUICK SUMMARY:IFO in Observation mode ~77 Mpc. All lights in LVEA, PSL and M/E stations are off. Wind is ≤10mph. EQ sei plot is nominal. Microseism plot is steady at ~.15microns/s.
Since we are not using some of our violin mode BLRMS monitors, I coopted six of them to make BLRMS of the DARM error signal from 60 to 180 Hz, with notches for the 60 Hz and 120 Hz mains lines. The channels are as follows:
In the longer term, we might consider adding new BLRMS to OAF which are expressly for this purpose.
On 10/14 we resumed the repair efforts on the beam tube enclosure 600 meters north of Mid-X. Somewhat of a slow start but we managed to clean the joints on 160 meters of enclosure and install metal strips and caulk 120 meters of upper enclosure.
The attached dtt screenshot shows the coherences of MICH and SRCL feedforward with the DCPD sum.
Note in particular the high coherence with SRCL FF between 2 and 5 Hz. In fact, most of the rms SRCL FF drive comes from below 5 Hz.
The attached dataviewer screenshot shows timeseries trends of the DCPD sum (below) and the FF signals (above) during lock acquisition. One can see that turning on the feedforward appears to increase the DCPD sum rms.
Also attached are TFs of the foton filters used for the feedforward.
TITLE: "10/16 [OWL Shift]: 07:00-15:00UTC (00:00-08:00 PDT), all times posted in UTC"
STATE Of H1: Observing at ~80 Mpc for the past 2 hours.
SUPPORT: Kiwamu, Sheila
SHIFT SUMMARY: Difficulty locking more than half of the shift. First I ran into Guardian issue not turning on the gains for INP1 and PRC1. Corey probably ran the a2l script and turned on the right gains by accident when he reverted the SDF differences (after a2l script failed) so we weren't aware of this happening. After couple of times turning the gains on by hand and eventually reloaded Guardian code as Kiwamu suggested, I ran into another problem and kept losing lock at ENGAGE_ASC_PART3. During phone calls with Sheila and Kiwamu we though it was an issue with the ASC. Kiwamu came over and after noticing a huge drop in RF90 prior to a lockloss he suggested I run an initial alignment. Turned out there were 2urad offset in TMSY. I didn't have any trouble locking arms green and DRMI so I didn't suspect a bad alignment (although I kept having trouble finding IR. Maybe that could have been a red flag?).
After the initial alignment we lost lock at Switch to QPDS once but everything went smoothly afterward. We got to NOMINAL_LOW_NOISE, ran the a2l script (had no trouble running it on my account), and finally Observing for the first time in almost 7 hours at 12:56 UTC.
Tonight I learned how 2 urad can make life miserable. My world will never be the same again.....
INCOMING OPERATOR: Jim
ACTIVITY LOG:
See Shift Summary.
I apolgize for not reloading the guardian with the INP1+PRC1 fix.
The A2L script does not touch the loop gains at all, that is all handled by gaurdian.
H1 had a lockloss at 4:10utc where there was no obvious culprit (nothing seismic, but I forgot to look at strip tools to see anything obvious).
Commissioning Mode for A2L: Once in Nominal Low Noise, ran the A2L script, but unfortunately it had errors, and left the SDF with diffs (after getting some consulting with Jenne able to Revert the SDF). So spent about another 22min running & troubleshooting A2L recovery. Will send Jenne errors in A2L script session.
Then went to Observation Mode at 5:10utc.
Operators: Do not run A2L script until Jenne troubleshoots script. (had "Permission denied" errors, so maybe there's an issue of running script logged in as ops?).
Will put this "pause" in running A2L in the new Ops Sticky Note page.
I was able to run the a2l script on my account. The script cleared all the SDF after it's done as Jenne advertised. All is well.
For lack of a better place to write this, I'm leaving it as a comment to this thread.
The problem was that the results directory wasn't write-able by the Ops accounts, although it was by personal accounts. I've chmod-ed the directory, so the A2L script should run no matter who you are signed in as.
Please continue running it (instructions) just before going to Observe, or when dropping out of Observe (i.e. for Maintenence).
The first attached plot (H1L1DARMresidual.pdf) shows the residual DARM spectrum for H1 and L1, from a recent coincident lock stretch (9-10-2015, starting 16:15:00 UTC). I used the CAL-DELTAL_RESIDUAL channels, and undid the digital whitening to get the channels calibrated in meters at all frequencies. The residual and external DARM rms values are:
residual DARM | external DARM | |
---|---|---|
H1 | 6 x 10-14 m | 0.62 micron |
L1 | 1 x 10-14 m | 0.16 micron |
The 'external DARM' is the open loop DARM level (or DARM correction signal), integrated down to 0.05 Hz. The second attached plot (H1L1extDARMcomparison.pdf) shows the external DARM spectra; the higher rms for H1 is mainly due to a higher microseism.
Some things to note:
The 3rd attached plot (H1L1DARMcomparison.pdf) shows the two calibrated DARM spectra (external/open loop) in the band from 20-100 Hz. This plot shows that H1 and L1 are very similar in this band where the noise is unexplained. One suspect for the unexplained noise could be some non-linearity or upconversion in the photodetection. However, since the residual rms fluctuations are 6x higher on H1 than L1, and yet their noise spectra are almost indentical in the 20-100 Hz band, this seems to be ruled out - or at least not supported by this look at the data. More direct tests could (and should) be done, by e.g. changing the DARM DC offset, or intentionally increasing the residual DARM to see if there is an effect in the excess noise band.
We briefly tried increasing the DCPD rms by decreasing the DARM gain by 6 dB below a few hertz (more specifically, it's a zero at 2.5 Hz, a pole at 5 Hz, and an ac gain of 1... it's FM5 in LSC-OMC_DC). This increased the DCPD rms by slightly less than a factor of 2. There's no clear effect on the excess noise, but it could be we have to be more aggressive in increasing the rms.
interesting, but do I interpret it right that you (on the experiment reported in the comment) assume that the DARM errorpoint represents the true DARM offset/position? I thought that it is the case at least at L1 that when DARM is locked on heterodyne, and the OMC is locked onto carrier (with the usual DC offset in DARM), then the power in transmission of the OMC fluctuates by several 10%. Assuming that the TEM00-carrier coupling to the OMC would be no different when DARM is locked to OMC trans. power, then also the 'true' DARM would fluctuate this much impressing this fluctuation onto DARM. This fluctuation should show up in the heterodyne signal then. So in this case increasing the DARM gain to reduce the rms would probably not do anything. Or?
I ran Dan's code to compare stationarity between two hours on Oct 5th and Oct 12th. The closure of the beam diverter on the 6th was thought to help stationarity in the 70-100hz region, so I included versions zoomed in on that frequency range.
I tried to pick times that were not affected by huge glitches / range drops. On the 5th the two hours were 1:00-3:00UTC and on the 12th 00:00-02:00UTC.
plots attached
Sheila, Jordan
Made the same plots to compare the stationarity during times when anthropogenic seismic was quiet / loud. The 1-3 and 3-10 hz seismic bands pick up around 14:00 utc weekdays, and the data seems to become more nonstationary in the 100-200 Hz band during this time.
On the 12th, there is some unknown stuff going on at lower frequencies, and the ~300 hz periscope peaks are still visible. But just looking at the 100-200 hz region shows correlation with ground motion. Also have the same correlation on the 14th (spectrum overall looks very stationary, though). Mechanism still unknown... scattering?