There were no indication of anything was going bad right before the lockloss. No glitches in the spectrum, no earthquake, nothing. The saturation alarm yelled ITMX and DRMI was unlocked. The SUS OMC SW watch dog tripped but seems to have uptripped itself. After that the Guardian wasn't able to turn ETMX ESD driver on and the reset switch kept flickling. Sheila is on her way to the site so I'm waiting for her. 

I noticed the light in the control room flickered at the exact time of the lockloss. I suspect a power glitch may have caused this lockloss.

I set the Operating Mode to UNKNOWN.

After several locklosses at REDUCE_CARM_OFFSET, I took it very slowly. I stayed at DRMI_LOCKED until the saturation alarm complained less about ETMX. Even though the wind speed is only 15-20 mph but PRM seems to wiggle a lot so I turned on the 90 mHz windy blend filters for all the corner station BSCs. The intent bit has been set to observing.

ER8 days 12 and 13. No restarts reported.

Times in UTC

925 - Took the IFO to DOWN for Kiwamu to work on more calibration measurements

1016 - H1SUSETMX Timing error cleared

1208 - NOMINAL_LOW_NOISE, but BS bounce was rung up and Kiwamu tried to damp it to no avail

1219 - Itbit set to Undisturbed

1416 - Lockloss (Wind is picking up, 20mph, but that shouldn't be a problem)

1431 - Lockloss @ DC_READOUT (everything looked good, not sure what happened unless it really is the wind)

1438 - Gardeners here for tumbleweed cleanup

1444 - Lockloss @ DARM_WFS

1454 - Lockloss @ CARM_ON_TR

1500 - Handing if off to Nutsinee

I don't know if this is a known issue, but today I noticed that when PRM was in the pre-defined misalgined position (set by Guardian), the M1_DAMP_L loop oscillated and kept saturating the DAC output in LF and RT coils all the time. While this does not pose any issue for lock acqusition or low noise lock, this may be an indication of some potential issue or something bad. Since I have no energy to further investigate this issue tonight, I am leaving it as it is.

I have completed a set of measurements that is necessary for nailing down the ETMY actuation scale factors. This is a third round of the measurements in order to study repeatability and systematic errors. The measurement data can be found at the follwong places.

• Full lock ETMY L3
  • aligocalibration/trunk/Runs/ER8/H1/Measurements/FullIFOActuatorTFs/2015-08-29/2015-08-29_H1SUSETMY_L3toDARM_LVLN_LPON_FullLock.xml
• Full lock ETMY L2
  • aligocalibration/trunk/Runs/ER8/H1/Measurements/FullIFOActuatorTFs/2015-08-29/2015-08-29_H1SUSETMY_L2toDARM_FullLock.xml
• Full lock ETMY L1
  • /aligocalibration/trunk/Runs/ER8/H1/Measurements/FullIFOActuatorTFs/2015-08-29/2015-08-29_H1SUSETMY_L1toDARM_FullLock.xml
• Full lock ETMX
  • aligocalibration/trunk/Runs/ER8/H1/Measurements/FullIFOActuatorTFs/2015-08-29/2015-08-29_H1SUSETMX_toDARM_FullLock.xml
• Full lock Pcal Y sweep
  • aligocalibration/trunk/Runs/ER8/H1/Measurements/FullIFOActuatorTFs/2015-08-29/2015-08-29_H1SUSETMY_PCALYtoDARM_FullLock.xml
• Full lock Pcal Y sweep in wide band (7 - 1200 Hz)
  • aligocalibration/trunk/Runs/ER8/H1/Measurements/PCAL/2015-08-29_PCALY2DARMTF_7to1200Hz.xml
• Full lock DARM open loop in wide band (7 -1200 Hz)
  • aligocalibration/trunk/Runs/ER8/H1/Measurements/DARMOLGTFs/2015-08-29_H1DARM_OLGTF_7to1200Hz.xml
• ALS Diff ETMX drive
  • aligocalibration/trunk/Runs/ER8/H1/Measurements/ALSDIFF/2015-08-29/2015-08-29_ALSDiff_ETMX_L3_HVHN.xml
• Mich lock ITMX drive
  • /aligocalibration/trunk/Runs/ER8/H1/Measurements/FreeSwingMich/2015-08-29/2015-08-29_H1SUSITMX_L2_State2_MICH.xml
• Mich lock open/closed loop
  • aligocalibration/trunk/Runs/ER8/H1/Measurements/FreeSwingMich/2015-08-29/2015-08-29_MICH_OLGTF.xml
• Mich free swing time series
  • aligocalibration/trunk/Runs/ER8/H1/Measurements/FreeSwingMich/2015-08-29/2015-08-29_H1MICH_freeswingingdata.xml
• Xarm locked ITMX drive
  • aligocalibration/trunk/Runs/ER8/H1/Measurements/FreeSwingMich/2015-08-29/2015-08-29_H1SUSITMX_L2_State2_XARM.xml
• X arm locked ETMX drive
  • aligocalibration/trunk/Runs/ER8/H1/Measurements/FreeSwingMich/2015-08-29/2015-08-29_H1SUSETMX_L3_HVHN_XARM.xml

After the 40mph wind storm died down, I began the locking procedure.  No full initial alignment was required, just some touching up of the PRMI SUSes.  The only hurdle was detailed in aLog 21016, which took around 30 minutes to overcome.  Kiwamu has been running Calibration excitations for a good portion of the lock stretch.

0:52 Started locking procedure

2:24 Locked on Low Noise

4:12 Started PCal/DARM measurement at Kiwamu's request

4:31 Switched to Observing

4:45 Switched to Calibration

6:13 Lockloss, PRM saturation

6:48 Locked Low Noise

I took higher resolution spectra of the supposed 41Hz HSTS roll mode tonight (see first attachment).  There are 2 peaks, however only the first peak has any coherance with anything.  The 2 peaks are at:

40.9375 Hz  (lots of DARM-PRC-SRC coherence)

41.0117 Hz  (no coherence with anything I looked at)

The second attachment shows the set of 41Hz peaks in 3 of the last lock stretches.  I attempted to use the ASC signals to check for coherence with DARM, but:

- the OSEM sensors on the HSTS suspensions are too noise, so see no coherence

- there is coherence with BOTH SRC and PRC, unfortunately, so hard to pin point where

- there is coherence with SRC1 which talks to SRM - is it cross-coupling thru ASC/LSC?

- there is no coherence with SRC2 likely because it is a noisy detector (AS DC), so can't tell if the SRM and SR2 combination that it talks to contribute to the 41Hz

- PRC1 not plotted, no ASC drive there, but witnessed that there is no coherence there

- PRC2 goes to PR3, so while there is coherence there (not plotted) it is likely because it is cross-coupling  from SRC to PRC

- IMC_TRANS_P not plotted, but witnessed no coherence, again too noisy of a detector?

A few minutes ago Travis started a CAL EY EXC as per Kiwamu's instruction.  I suggested that we see if the starting this EXC would kick the IFO out of OBSERVATION mode.  Of course it didn't (so he had to hit the UNDISTURBED button anyways) because according to Jamie's new screen, it shouldn't. 

My question is, why would we not monitor excitations on all machines?  (Ones that aren't being monitored are the ones with unlit grey boxes in the ODC column.  Screen snapshot below.)

I wish I could some how follow the grey bit back through ODC screens and find what it is or isn't looking at but the channel names are very unfamiliar and the nested screens are very difficult to understand...  For example, why is the "ISC_EX" bit grey?  There is no channel name when I try to middle click over it, so I can't trace it anyways.

Recall, you can only open the screen directly from medm via the macro comand:

medm -x -macro "IFO=H1" EXCITATION_OVERVIEW.adl

I have contacted the landscaping crew to remove the tumbleweeds that have accumulated on the X and Y arm access roads. They will begin tomorrow at 7 A.M. on the X-Arm.

While bringing the IFO to Low Noise lock for the first time today, the ISC_LOCK Guardian got stuck at ENGAGE_ISS_2ND_LOOP.  After unsuccessfully trying to re-request NOMINAL_LOW_NOISE in hopes that it would unstick itself, I asked JeffK if he had any ideas.  We dug into the ISC_LOCK code, which led us to the IMC_LOCK Guardian where the ISS requests live.  Not seeing anything obvious, we ran out of ideas and called Sheila (the on-call commissioner).  She suggested that we request a lower state in the IMC_LOCK Guarding (PREPARE_ISS).  I did so, and with ISC_LOCK still requesting ISS_ON in the IMC_LOCK Guardian, it ran through without issue.  Take-away message: if ISC_LOCK gets stuck in ENGAGE_ISS_2ND_LOOP again, open IMC_LOCK (still in Managed) and request PREPARE_ISS.

J. Kissel, K. Izumi

I've finished preliminary analysis on the data from Wednesday and Friday's suites of actuation function measurements (see LHO aLOGs 20940 and 21005). I've found that all methods, PCAL (using a very-well-calibrated power meter to measure the power of light pushing the test mass for reference), ALS DIFF (using the DIFF VCO oscillator as a frequency reference), and Free-swinging Michelson (using the red laser's wavelength for reference) are consistent with each other. Further, they identify that there are systematics in a simple model of the QUAD actuation strength that we've been using. However, without quoting any precisely quantified uncertainty (because the residuals are frequency dependent), I imagine all methods will agree to better than 10%. One good result: it appears that after releaving the charge post-ER7 (LHO aLOGs 19234 and 19211), and continued efforts to measure and keep that charge small (e.g. LHO aLOG 20968), have cleaned up the electrostatic drive strength, which are now far more consitstent between ETMX and ETMY (at roughly 2e-10 [N/V^2]).

As a tease (which hopefully won't cause too much alarm or confusion -- be prepared for these to change a lottle), I attach plots of the current residuals between model and measurement. 

Bear with me while I take the next steps, which are to
- functionalize the analysis scripts so we can easily process future measurements, 
- have those functions spit out their individual measurement results so they can be compared with each other (the comparison of which is another function to write), and
- make sure that all the scripts are using the output of the latest DARM model and parameter set, instead of recreating a naive model from the matlab QUAD's [m/N] and knowledge of the electronics chain.
- finish processing results from all the of the electronics chain measurements to identify if frequency-dependent systematics lie in there
- Update / refine the DARM model parameters to squash the frequency-dependendent residual to as small as possible, such that we can be confident in professing number with properly quantified 
uncertainty.

What has NOT been included in the naive actuation model:
- 16k IOP up-sampling filter
- Analog AA filter
- Any of the un- or poorly-compensated poles and zeros of the ESD drivers
- The recently found mis-match between expected and reality regarding the UIM driver's poles and zeros (LHo aLOG 20846)
I have a high degree of confidence that these are the reasons for the residual frequency dependence. In other words, these be resolved once I switch to using the full DARM model's actuation chain. That being said, suggestions are welcome as to what else the discrepancies might be.

-----------
We tried to get another round of measurements today, but we got totally blasted by a 40+ [mph] wind storm.
Kiwamu will be coming back tonight to make the measurements once the wind has died down (which it has already begun to do).

-----------
The latest versions of the analysis scripts have been committed to
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/ER8/H1/Scripts/
ALSDiff/analyze_alsdiff_data_20150826.m
ALSDiff/analyze_alsdiff_data_20150828.m
FreeSwingMich/analyze_mich_freeswinging_data_20150826.m
FreeSwingMich/analyze_mich_freeswinging_data_20150828.m
PCAL/analyze_pcal_data_20150826.m
PCAL/analyze_pcal_data_20150828.m

Over the last ~5 days, nearly 100 SDF channels have gone into alarm.  We should probably link these to the INTENT bit, since many of these are actually real configuration control changes of the IFO, yet currently do not dictate any GO/NO GO of observation mode.  When connected to the intent bit, it will force commissioners and operators to address these changes in realtime, rather than let them stack up for me to reinvent every 5 days.

Since super-winds (and calibrations) have the IFO down, I've taken the opportunity to work on these - so far I've cleaned up:

- ETMX and ETMY L1 and L2 damping loop outputs enabled last Tuesday around the maintenance period - maybe the BURT pushed these buttons.  I  verified that the SAFE file sets the gain of the loop to be zero and the IN and OUTPUTS are ON.  Guardian then controls the gain.

- Accepted a few pages of offset changes, and the extra AS_B_RF45_AWHITEN_SET2 due to Evan/Stefan running the dark offsets script/commissioning last Thur night (alog 20976).  I'll wait for them to comment that the 1st attached SDF diffs are 1) their intended gain changes as it's vague in their alog, and 2) if they are ready to keep/accept them.

- Since SDF couldn't write the very small ~ 10e-19 CALCS epics values to the SAFE.snap file (commissioned AUG 11 alog 20452), I wrote them in by hand and then hit LOAD TABLE on the CALCS SDF.  All of the values cleared, since now they match the very small values loaded in their respective medms.  I've committed the CALCS safe.snap to svn.

- ALS X and Y - I need someone to point me to an alog regarding why the ALS_WFS_DOF_3 gains changed on both X and Y in the middle of the night on Thur night (2am Fri - see second SDF diff attachment.)

(All time in UTC)

15:42 Wind picking up speed reaching 40 mph. BNS range is dropping slightly.

16:00 Lockloss. Wind reaching 50mph.

16:05 ODC observatory mode didn't bring itself out of OBSERVING. Stayed there for 5 mins before I realized it.

16:06 Took the interferometer to down after several locklosses before DRMI. 

17:00 Rich to LVEA

17:11 Attempted locking failed

18:04 Rich back

19:57 Nutsinee driving down X and Y arms to check on tumbleweed.

20:25 Nutsinee back

20:28 Wind reading 60 mph. Locking won't be possible for a while.

21:08 Kiwamu and Rich to CER

21:30 Rich back

22:30 Kiwamu doing some electronic works. IMC will be on and off.

Other notes:

- EY dust alarm went off. >0.3u reads 16028.6 PCF, >0.5y reads 1285.7 PCF at the time.

- As Daniel requested, I added graphics indicate operating mode on the Ops Overview. The graphics visibility is calculated using H1:ODC-OBSERVATORY_MODE. I haven't had a chance to test if it works properly but so far the "environment" badge shows up as it's supposed to.

- Tumbleweeds are flying! Slowly accumulating along the X arm but still far from blocking the road.

- We haven't had a stable lock since the wind reached 40mph.

Conclusion:
For those liking a quick summary, there isn't a significant difference between the RF field levels at LHO and LLO

Overview:
A series of measurements were taken with the goal of comparing the ambient RF fields at LHO to those recently measured at LLO by Patrick Meyers and Rai Weiss.  The LLO measurements focused on the RF fields in the vicinity of ISC Rack C4 in the control equipment room (CER).  Nearly 200 separate readings were taken.

Method:
A predominantly magnetic field probe was sent from LLO to LHO such that the measurements be a fair comparison.  The probe consists of copper wire wound around a small RF ferrite core similar to those used in the iLIGO WFS.  A probe such as this has a directionality depending on the relative angle of the sensing coil to the driving magnetic field.  At each point of measurement, the maximum RF level was recorded by choosing the optimum angle to hold the sense coil.  There is a large (up to 10dB or more) error bar in this type of near-field measurement as movements of an inch or so can greatly influence the measured value of RF.  Only in the far-field, in the absence of sources of reflections, does it become more textbook in its response.

In addition to the magnetic field probe Rai made, I made two matched probes (one was sent to LLO prior to my trip as a basis for future comparisons).  My probes are simple electric field antennae consisting of a 10cm monopole mounted on a square aluminum ground plate measuring 20cm on each side.  The ground plate serves to lessen the proximity effect of nearby objects (hands included).  I used this rudimentary probe to establish an approximate maximum RF field level at chest height about 3 feet from the front of a rack (CER and LVEA) for various frequencies of interest.

The LLO study found that the largest RF fields in the CER are associated with the three VCOs used in the LVEA (ALS-DIFF, ALS-COM, and PSL).  This result holds true for LHO.  The readings make no attempt to catalog the magnitude of each individual peak, instead the largest one was recorded for a given physical location.

Results:
The full results including the 200 or so power readings are being written into a separate document.  Summary results only are presented here.

1.  CER first and second harmonics of the VCOs - RF fields measured with Rai's magnetic field probe range from -60 to -40 dBm in and around the spigots of the RF patch panels and chassis mounted RF units for both the first and second harmonics of the drive frequency (nominally 79.4MHz fundamental).  Maximum RF readings tend to congregate around the baluns that are used to break low frequency ground loops.

2.  A survey using the 10cm electric field probe at chest height, 3 feet from the front of the ISC-C4 rack shows the following typical levels:
VCO fundamental frequency - -68dBm
9.1MHz - < instrument noise floor (-105dBm)
18.2MHz - -99dBm
27.3MHz - -90dBm
36.4MHz - -84dBm
45.5MHz - -78dBm
80MHz (exact, not VCO frequency) -80dBm

3.  A survey using the 10cm electric field probe at chest height, 3 feet from the front of the field racks, ISC R1 and PSL R1 show:
PSL VCO 1st and 2nd harmonic - -60dBm/-57dBm measured in front of PSL-R1, -69dBm fundamental in front of ISC-R1 (the other two VCOs are 10 to 20dB down).  Noted -50dBm 2nd harmonic of ALS DIFF VCO in front of ISC-R1.  The only other signals of any size are the PSL 21.5MHz and 35.5MHz (for FSS and PMC locking).  These PSL frequencies are ~-80dBm everywhere in front of the whole row of racks (ISC to PSL).

4.  Using Rai's magnetic field probe, a signal level of up to -28dBm can be seen emanating from a leaky cable (see attached photo) coupling the PSL VCO to the PSL VCO Amplifier (D1201423) on the front of the PSL-R1 rack.  The radiation is partly due to a low quality braided cable (Pasternak Inc.)and partly due to a balun that is probably not needed anyway as the cable run it serves is only ~10feet.

An isolated test was performed on the RF baluns (see attached photo) commonly encountered in the distribution system.  The electric field antenna was positioned (see attached photo) about 1 foot away from the balun under test.  Adding the balun to the end of the cable increases the received RF power by a factor of ~1000.  There is a provision in each balun to include some capacitors (not included in our deployment).  Among other functions, these capacitors provide an RF ground for the metal body of the balun.  Without this ground, the internal wires (not very RF-ish, but probably OK) are free to radiate.  Adding the capacitors to a balun caused the observed radiation to drop to the background of the measurement equal to the no-balun case.  It is not a pill to be taken lightly, as this will no doubt change the phase of signals receiving this "fix".  Remember, as of now, there's no smoking gun at LHO pointing to a problem with radiated RF.  However, devices that can couple out also tend to couple in, so it offers a path for environmentally modulated RF to reenter and sum with the RF on a cable.

A test device consisting of a small handheld PLL with internal FM (100Hz or so) could be built such that it would be locked to a particular LIGO RF distribution system frequency and provide a small transmitting antenna.  The FM modulated signal could then be probed around to see if any part of the demodulation components are particularly vulnerable (broken shields, loose connectors, etc.) by observing the demodulated signal perhaps while the IFOs are locked.

Kiwamu, Nutsinee

As we were trying to relock the ifo after several locklosses due to high wind (50mph), we noticed the sideband signals wiggled a lot before another lockloss at DC_READOUT (wind speed ~35-40 mph). We found a coherence between POP18, POP19, POP_A_LF, AS90 and PRM, SRM, BS which indicates that the DRMI was unstable. The BS ISI Windy blends weren't turned on. 

The dtt template for DARM open loop measurement has been updated to take the new elliptic filter (alog 20612) into account. This covers a frequency band of 7-1200 Hz. Additionally, a few frequency points are slightly shifted to avoid notchy places.

The dtt file is saved in SVN at

aligocalibration/trunk/Runs/ER8/H1/Measurements/DARMOLGTFs/2015-08-28_H1DARM_OLGTF_7to1200Hz.xml