Displaying reports 56581-56600 of 78050.Go to page Start 2826 2827 2828 2829 2830 2831 2832 2833 2834 End
Reports until 19:59, Monday 28 September 2015
H1 General
travis.sadecki@LIGO.ORG - posted 19:59, Monday 28 September 2015 (22041)
OPS Eve mid-shift summary

Nothing of note here.  H1 is in Observing and running smooth and steady for 7 hours now.  4 ETMy saturation alarms since the start of the shift.  RF45 is looking good. 

H1 AOS (FMP)
jodi.fauver@LIGO.ORG - posted 19:54, Monday 28 September 2015 (22040)
LHO Delivery Log
In case it is ever of use, I asked Christina and Terry G. to try and log the arrival and departure times of delivery vehicles for two weeks. UPS and FedEx do daily deliveries: various other vendors deliver occasionally. If necessary, we can make inquiries as to Gross Vehicle Weight etc. 
Non-image files attached to this report
H1 General
betsy.weaver@LIGO.ORG - posted 18:42, Monday 28 September 2015 - last comment - 23:06, Monday 28 September 2015(22039)
ASC DHARD Y FM2 enabled during observe segment

Attached is a snapshot illustrating which observe mode segment had the ASC DHARD Yaw FM2 filter engaged.  Recall that the filter was engaged a few times over the last week in an attempt to ride out a species of ground motion.  In all but one of the cases when this FM2 filter was engaged, the IFO Observation Intent bit was NOT set.  The following is the one segment when the filter was engaged:

 

H1 Single IFO Segment  #30 from https://ldas-jobs.ligo.caltech.edu/~detchar/summary/O1/

(Segment lists are shown via the blue pop-open banners across the bottom of the page - see specifically H1:DMT-ANALYSIS_READY:1)

30	1127313107	1127329701	16594
Images attached to this report
Comments related to this report
marissa.walker@LIGO.ORG - 23:06, Monday 28 September 2015 (22043)

Laura Nuttall, Marissa

I've repeated what Laura did in alog 21820 for this time, to compare the glitch rate between times that did and did not have the DHARD Y boost and determine whether this should have much of an impact on the transient searches' backgrounds. Unfortunately, this lock segment had some really bad RF45 noise so it's not ideal for evaluating glitch rates (since a lot of this time will be cut out from the search backgrounds), but it's what we have...

I've attached the omicron glitchgrams and trigger rates for the time that the filter was turned on, and for the same amount of time just after it was turned off. The overall rate of low SNR triggers is about the same during both segments, with some times of increased rate of higher SNR triggers while the filter was engaged, most likely due to the RF45 noise. Similarly, the glitchgrams' structures do not appear significantly different between the two segments, besides the awful RF45 times.

From this comparison, I would agree with Laura's earlier conclusion that this filter does not appear to have a significant effect on the background.

Images attached to this comment
H1 General
nutsinee.kijbunchoo@LIGO.ORG - posted 16:05, Monday 28 September 2015 (22036)
Ops Day Shift Summary

TITLE: 09/28 [DAY Shift]: 15:00-23:00 UTC (08:00-16:00 PDT), all times posted in UTC

STATE Of H1: Observing at ~70 Mpc.

SUPPORT: Peter, Mike, Laura

QUICK SUMMARY: Reducing RF45 modulation index definitely helps with the glitch rate. Lockloss twice within the shift due to an earthquake and PSL tripped. Had no problem relocking. Wind speed ~10mph tilts the ground and increase the seismic activity in the earthquake band (0.03-0.1Hz) to 0.05 um/s.

INCOMING OPERATOR: Travis

ACTIVITY LOG:

Morning Meeting:

- We have had good weekend locking, but not a good running. Driver swap tomorrow.

 

15:51 Lockloss due to an earthquake. Adjusted PR3 to maximize COMM beatnote. Touched BS to get DRMI locked at the right mode.

16:27 Back to Observing.

17:37 RF45 was acting up. Dropped the intent bit to reduce RF45 mod index. Kept the configuration as Laura suggested and continued to Observe.

18:12 Lockloss due to PSL tripped. Peter turning the laser back on.

           Praxxair on site. Going to Mid Y. Intent bit dropped.

18:20 Peter back

18:46 Locked again at NOMINAL_LOW_NOISE but not Observing. Waiting for Praxxair to leave site.

19:49 Praxxair hasn't moved for a really long time. I switched the bit to Observing.

19:51 Out of Observing. Praxxair leaving site.

19:56 Back to Observing.    

Images attached to this report
H1 INJ (INJ)
cregg.yancey@LIGO.ORG - posted 15:27, Monday 28 September 2015 - last comment - 14:39, Tuesday 29 September 2015(22034)
HWInjReport daily run 1127423695 - 1127510095

Parameters for report:

GPS Start Time = 1127423695 # Beginning of time span, in GPS seconds, to search for injections
GPS End Time = 1127510095 # Ending of time span, in GPS seconds, to search for injections
Check Hanford IFO = True # Check for injections in the Hanford IFO frame files.
Check Livingston IFO = True # Check for injections in the Livingston IFO frame files.
IFO Coinc Time = 0.01 # Time window, in seconds, for coincidence between IFO injection events.
Check ODC_HOFT = True # Check ODC-MASTER_CHANNEL_OUT_DQ channel in HOFT frames.
Check ODC_RAW = True # Check ODC-MASTER_CHANNEL_OUT_DQ channel in RAW frames.
Check ODC_RDS = True # Check ODC-MASTER_CHANNEL_OUT_DQ channel in RDS frames.
Check GDS_HOFT = True # Check GDS-CALIB_STATE_VECTOR channel in HOFT frames.
Report Normal = True # Include normal (IFO-coincident, consistent, and scheduled for network injections and consistent and scheduled for IFO injections) injections in report
Report Anomalous = True # Include anomalous (non-IFO-coincident, inconsistent, or unscheduled) injections in report

----

No scheduled injections or non-occurring injections were found.

There was a CAL_INJ reset that occurred only in H1, CALRESET 1127480460.000 (H1). However, it has the anomaly that it appears in ODC HOFT and GDS HOFT frames but not in ODC RAW or ODC RDS frames.  This same anomaly was observed with several CBC injections in L1 during the daily period 1127163296 - 1127249696.

Non-image files attached to this report
Comments related to this report
cregg.yancey@LIGO.ORG - 14:39, Tuesday 29 September 2015 (22078)

The anomalies reported here are likely due to the same bug that caused the anomalies as reported in https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=21971.

H1 PSL
betsy.weaver@LIGO.ORG - posted 15:21, Monday 28 September 2015 - last comment - 17:21, Monday 28 September 2015(22033)
IMC Power Increase during NOMINAL_LOW_NOISE, ISS 2nd loop reference signal adjustments

B. Weaver, J. Oberling

After this morning's PSL trip there was a 0.5W increase in IMC-PWR_IN, observed ~15 minutes after reaching NOMINAL_LOW_NOISE.  We started digging in the Guardian code and rediscoverd that the ISS diffracted power gets adjusted by a software PID loop located in the IMC_LOCK guardian; this adjustment is done via changing the ISS 2nd loop reference signal.  At the start of a lock stretch this PID loop is necessary to keep the ISS diffracted power around the predetermined nominal value of 8%.  However today we witnessed that when the diffracted power trended towards the upper threshold (set in the IMC_LOCK guardian code) of 10%, the IMC_LOCK turned on the PID loop, thus increasing the measured IMC-PWR_IN by ~0.5W.

Images attached to this report
Comments related to this report
betsy.weaver@LIGO.ORG - 15:28, Monday 28 September 2015 (22035)

Looking back 16 days we discovered 2 more cases of the IMC_LOCK guardian turning on the ISS PID loop during a NOMINAL_LOW_NOISE (and observing) lock stretch.  Attached is the 16 day trend and the 2 examples.  The 2nd example was 30 hours into last week's 46 hour lock stretch.  Also note, in the 16 day trend, the continued power discrepancy from lock to lock.

Looking at the 16 day trend, by eye it seems the ISS diffracted power is hugging the upper threshold of 10% more often then not, hovering around 9%.  This might be normal acceptable behavior, however we were surprised to see that a PID loop was increasing power in the middle of an observing lock.  Will follow up with commissioners.

Images attached to this comment
evan.hall@LIGO.ORG - 16:17, Monday 28 September 2015 (22037)

What do the in- and out-of-loop signals for the outer loop look like during these events? (I.e., SUM14 and SUM58.)

jeffrey.kissel@LIGO.ORG - 17:21, Monday 28 September 2015 (22038)
B. Weaver, J. Kissel,

Not sure what Evan wants with the "SUM14" and "SUM58" channels, so I found what channels are stored in the frames for the ISS, and used my vague knowledge of how the ISS SECOND LOOP works, and chose
H1:PSL-ISS_SECONDLOOP_SUM14_REL_OUT_DQ
H1:PSL-ISS_SECONDLOOP_SUM58_REL_OUT_DQ
and reproduced Betsy's plots with trends of those channels in addition to the original channels. 

I'll leave it to Evan to interpret the results, 'cause we don't know how.

Let us know if you need anything different, Evan (or on a different scale, or whatever). 
Images attached to this comment
H1 General
nutsinee.kijbunchoo@LIGO.ORG - posted 13:22, Monday 28 September 2015 (22031)
Hanford Site Alarm

Fil came to let me know that the alarm at Hanford site is going off. They called earlier that there will be an alert system testing between 12:30-13:30.

H1 General
nutsinee.kijbunchoo@LIGO.ORG - posted 13:10, Monday 28 September 2015 (22030)
Back to Observing 19:56 UTC

I switched to Observing a bit at 19:49 after Praxxair hadn't moved for a really long time. I went back to comissioning then the truck took off from Mid Y at 19:51. And back to Observing when it went back to Rt. 10.

The PSL AOM diffracted power was dropping but now stable within desired range (8%). Peter went to turn on the laser Watchdog.

Images attached to this report
H1 ISC
stefan.ballmer@LIGO.ORG - posted 12:26, Monday 28 September 2015 (22026)
New oversion of ODC screens
Downloaded Dunca's M.'s new ODC overview screens. They are now linked to the sitemap. The old one are still available.
cds/h1/medm/SITEMAP.adl is in the svn - revision 11744
For what it's worth - I also noticed that some ODC settings for IM's and HTTS's are not up to date.

H1 General
nutsinee.kijbunchoo@LIGO.ORG - posted 11:13, Monday 28 September 2015 - last comment - 13:08, Monday 28 September 2015(22023)
Lockloss 18:11 UTC

PSL tripped.

Comments related to this report
peter.king@LIGO.ORG - 11:48, Monday 28 September 2015 (22024)
Sitting in the control room I heard something about a lock loss.  I looked at the monitor that displays various cavity
transmissions and noticed that the laser had tripped.  I went into the diode room.  The Beckhoff computer indicated
that the laser switched off due to the power watchdog being kicked.

    The power watchdog performed as it should.

    However we should make it routine to reset the power watchdog every maintenance day.  Something we have mentioned
but perhaps were not as diligent about it as we should be.

    All the PSL related servos were up by the time I returned to the control room.

    Attached is a plot of the laser power since the last time (I believe) the watchdog was reset back on
Sept. 1st.
Images attached to this comment
nutsinee.kijbunchoo@LIGO.ORG - 11:52, Monday 28 September 2015 (22025)

Locked again at NOMINAL_LOW_NOISE. RF45 MODE reduced to 22.2 dB after it was reset to 23.2 by Guardian after the lockloss. Currently not Observing due to Praxxair (a really big truck) on site.

peter.king@LIGO.ORG - 13:08, Monday 28 September 2015 (22029)
When the laser was restarted the main screen indicated that the laser power was 34.7 W.  Instead of turning
on the watchdog there and then I decided to wait and let the power stabilise out before setting the dog loose.
Turned on the watchdog at ~13:05 UTC, the power indicated on the screen was 34.1 W.
H1 SEI
hugh.radkins@LIGO.ORG - posted 11:13, Monday 28 September 2015 (22022)
WHAM5 ISI Top model Modelified to Temporarily Fix Rogue Ext Trip Issue

re Int Issue 1127, WP 5521.

Have modified the WHAM5 Top Level Model to terminate the output of the ADC and ground the input of the Coil Driver Corner2 Voltage monitors.

This will eliminate the false Rogue Excitation WD Trips of which this platform has been suffering.  BTL identified the cause finding the bad monitor output.

This is temporary until we swap out the driver and look for a cause in the monitor circuit.

On Tuesday 29 Sept, the model will be installed and the FE restarted after taking the platform down to safe or offline.

After restart, the SDF will have to be repointed to the OBSERVE.snap

Attached is an image of the modified model area: the two don't look like the others.

Modified model commited to svn rev 11742.

Images attached to this report
H1 General
nutsinee.kijbunchoo@LIGO.ORG - posted 10:50, Monday 28 September 2015 (22021)
Dropped RF45 modulation index by 1 dB

The glitch rate hasn't been doing very well in the past hour (since I relocked the ifo) so I dropped the intent bit and reduced the modulation index (17:37 UTC) by 1 dB. The  H1:LSC-MOD_RF45_AM_RFSET value is now 22.2 instead of 23.2. I went back to observing with this configuration and see if it helps with the glitch rate. So far the DMT Omega has been looking much cleaner in the past 10 minutes.

H1 General
nutsinee.kijbunchoo@LIGO.ORG - posted 09:12, Monday 28 September 2015 - last comment - 09:27, Monday 28 September 2015(22018)
Lockloss 15:50:47 UTC

Lockloss after 60 hours locking at NOMINAL LOW NOISE (beat the old record of 46 hours from three days ago). There's a 5.4M earthquake in Argentina at a depth of 198.5km happened right around the time. Terramon suggested this earthquake shouldn't drop us out of lock but LLO has also dropped lock at the same time. USGS reported no bigger earthquake.

Comments related to this report
nutsinee.kijbunchoo@LIGO.ORG - 09:27, Monday 28 September 2015 (22019)

Back to Observing 16:27 UTC.

H1 DetChar (DetChar)
keith.riles@LIGO.ORG - posted 20:05, Saturday 26 September 2015 - last comment - 10:13, Monday 02 November 2015(21982)
Narrow lines in H1 DARM in O1 week 1
Executive summary: 
  • In regard to narrow lines, early O1 data resembles early ER8 data: a pervasive 16-Hz comb persists throughout the CW search band (below 2000 Hz); there is a notable 1-Hz comb below 100 Hz (0.5-Hz offset); and other sporadic combs persist.
  • On the other hand, there are distinct improvements: noise floor is cleaner nearly everywhere and substantially lower in the 10-70 Hz band; non-linear upconversion around quad violin modes and harmonics is much reduced; some combs and isolated lines have disappeared; and the OMC alignment dither frequencies have moved out of the CW search band (hurray!).
  • Oh the third hand, new artifacts have appeared or strengthened: a sporadic 8-Hz comb suspected before is confirmed; a 1-Hz comb (no offset) has emerged below 70 Hz; a broad bulge appears in the 1240-1270 Hz band.
Details: Using 104.5 hours of FScan-generated, Hann-windowed, 30-minute SFTs, I have gone through the first 2000 Hz of the DARM displacement spectrum (CW search band) to identify lines that could contaminate CW searches. This study is very similar to prior studies of ER7 data and ER8 data, but since this is my first O1 report, I will repeat below some earlier findings. Some sample displacement amplitude spectra are attached directly below, but more extensive sets of spectra are attached in zipped files. One set is for O1 sub-band spectra with labels (see code below), and one set is an overlay of early ER8 spectra (50 hours) and the early O1 spectra. As usual, the spectra look worse than they really are because single-bin lines (0.5 mHz wide) appear disproportionately wide in the graphics A flat-file line list is attached with the same alphabetic coding as in the figures. Findings:
  • A 16-Hz comb pervades the entire 0-2000 Hz band (and well beyond, based on daily FScans)
  • A typically much weaker and sporadic 8-Hz comb (odd harmonics) is also pervasive - previously suspected, now confirmed (all harmonics are labeled in figures, even when not visible)
  • A 1-Hz comb with a 0.5-Hz offset is visible from 15.5 Hz to 78.5 Hz (slightly wider span than before)
  • A new 1-Hz with zero offset is visible from 20.0 Hz to 68.0 Hz
  • A 99.9989-Hz comb is visible to its 8th harmonic (was previously visible to its 13th harmonic)
  • The 60-Hz power mains comb is visible to its 5th harmonic (was previously visible to its 9th harmonic)
  • There is a sporadic comb-on-comb with 0.088425-Hz fine spacing that appears with limited spans in three places near harmonics of 77, 154 and 231 Hz (ambiguity in precise fundamental frequency)
  • There is a 31.4149-Hz comb visible to its 2nd harmonic
  • The OMC alignment dithers have been moved to above 2000 Hz (thanks!)
  • Upconversion around the quad violin modes and their harmonics is much reduced, although the strengths of the higher harmonics themselves remain high. To be more specific, the fundamental and higher harmonics of the upconversion itself (integer harmonics) due to the fundamental violin harmonics are highly suppressed, while the higher harmonics of the violin modes themselves (not integer harmonics) remain high.
  • A number of previously seen combs are no longer apparent: 59.3155 Hz, 59.9392 Hz, 59.9954 Hz and 75.3 Hz
  • A variety of single lines have disappeared, and new ones have appeared (see attached line list)
  • Compared to early ER8 data, the noise floor is slightly lower in most of the band and significantly lower in the 10-70 Hz band, but there is a significant new bulge in the 1240-1270 Hz band
Line label codes in figures: b - Bounce mode (quad suspension) r - Roll mode (quad suspension) Q - Quad violin mode and harmonics B - Beam splitter violin mode and harmonics C - Calibration lines M - Power mains (60 HZ) s - 16-Hz comb e - 8-Hz comb (odd harmonics) O - 1-Hz comb (0.5-Hz offset) o - 1-Hz comb (zero offset) H - 99.9989-Hz comb J - 31.4149-Hz comb K - 0.088425-Hz comb x - single line Figure 1 - 0-2000 Hz (Early O1 data with line labels) Figure 2 - 20-100 Hz sub-band (shows complexity of combs below ~70 Hz Figure 3 - 1300-1400 Hz sub-band (shows how clean the noise floor is away from 8-Hz, 16-Hz lines at high frequencies Figure 4 - 0-2000 Hz (Early ER8 and O1 data comparison, no labels) Attachments: * Zip file with miscellaneous sub-band spectra for early O1 data (with line labels) * Zip file with sub-band spectra comparing early ER8 and early O1 data * Flat-file list of lines marked on figures
Images attached to this report
Non-image files attached to this report
Comments related to this report
keith.riles@LIGO.ORG - 12:53, Monday 28 September 2015 (22027)
A matlab file (37 MB) containing the averaged inverse-noise-weighted spectrum from the first week can be found here: 

https://ldas-jobs.ligo.caltech.edu/~keithr/spectra/O1/H1_O1_week1_0-2000_Hz.mat

Because of the way multiple epochs are handled, the matlab variable structure is non-obvious.
Here is how to plot the full spectrum after loading the file:  semilogy(freqcommon,amppsdwt{1,1})
nelson.christensen@LIGO.ORG - 07:39, Sunday 18 October 2015 (22614)
Keith has found:
"There is a sporadic comb-on-comb with 0.088425-Hz fine spacing that appears with limited spans in three places near harmonics of 77, 154 and 231 Hz (ambiguity in precise fundamental frequency)"

Using the coherence tool, we have seen coherence between h(t) and a number of auxiliary channels that shows this comb around 77 Hz. Seems to be around the input optics, in channels:
H1:PEM-CS_MAG_LVEA_INPUTOPTICS_Z_DQ  
H1_SUS-ITMY_L1_WIT_L_DQ
H1:SUS-BS_M1_DAMP_L_IN1_DQ      
H1_SUS-ITMY_L1_WIT_P_DQ
H1:SUS-BS_M1_DAMP_T_IN1_DQ          
H1_SUS-ITMY_L1_WIT_Y_DQ
H1:SUS-BS_M1_DAMP_V_IN1_DQ          
H1_SUS-ITMY_L2_WIT_L_DQ
H1:SUS-BS_M1_DAMP_Y_IN1_DQ         
H1_SUS-ITMY_L2_WIT_Y_DQ

See the attached figures.

Nelson, Soren Schlassa, Nathaniel Strauss, Michael Coughlin, Eric Coughlin, Pat Meyers
Images attached to this comment
soren.schlassa@LIGO.ORG - 11:09, Wednesday 21 October 2015 (22673)
The structure at 76.4Hz Nelson listed some channels for above shows up in at least 50 other channels. 

Greatest coherence is consistently at 76.766 Hz, second greatest is (mostly) consistently at 76.854Hz. 

Spacing between the two combs is about 0.0013Hz.

The epicenter seems to be the INPUTOPTICS/the SUS-BS and SUS-ITM* channels, like Nelson said (see below for fuller list).

The plots above are pretty typical, but I have plots for all channels listed and can post any more that are useful. Most or all channels showing the comb with max coherence greater than 0.1 are listed below. Max coherences over 0.2 are marked below as strong, and max coherences under 0.15 as weak. Those marked strongest are around 0.22. I haven't included anything of max coherence <0.1 but I'm sure there are many.

H1:ASC-AS_A_RF36_I_PIT_OUT_DQ (weak)
H1:ASC-AS_A_RF36_I_YAW_OUT_DQ
H1:ASC-AS_A_RF36_Q_PIT_OUT_DQ
H1:ASC-AS_A_RF36_Q_YAW_OUT_DQ (weak)
H1:ASC-AS_B_RF36_I_YAW_OUT_DQ
H1:ASC-AS_B_RF36_Q_YAW_OUT_DQ (strong)
H1:ISI-BS_ST2_BLND_RZ_GS13_CUR_IN1_DQ (strong)
H1:ISI-BS_ST2_BLND_Z_GS13_CUR_IN1_DQ (strong)
H1:ISI-HAM2_BLND_GS13RZ_IN1_DQ
H1:ISI-HAM2_BLND_GS13Z_IN1_DQ
H1:ISI-HAM3_BLND_GS13Z_IN1_DQ (strong)
H1:ISI-HAM5_BLND_GS13RZ_IN1_DQ
H1:ISI-HAM5_BLND_GS13Z_IN1_DQ
H1:ISI-HAM6_BLND_GS13RZ_IN1_DQ
H1:ISI-ITMX_ST2_BLND_RX_GS13_CUR_IN1_DQ (weak)
H1:ISI-ITMX_ST2_BLND_Z_GS13_CUR_IN1_DQ (strong)
H1:ISI-ITMY_ST1_BLND_RZ_T240_CUR_IN1_DQ (weak)
H1:ISI-ITMY_ST1_BLND_Y_T240_CUR_IN1_DQ (weak)
H1:ISI-ITMY_ST2_BLND_RZ_GS13_CUR_IN1_DQ (strong)
H1:ISI-ITMY_ST2_BLND_Z_GS13_CUR_IN1_DQ (strong)
H1:LSC-PRCL_IN1_DQ
H1:PEM-CS_LOWFMIC_LVEA_VERTEX_DQ (strong)
H1:PEM-CS_MAG_LVEA_INPUTOPTICS_Y_DQ (strongest)
H1:PEM-CS_MAG_LVEA_INPUTOPTICS_Z_DQ (strong)
H1:SUS-BS_M1_DAMP_L_IN1_DQ (strongest)
H1:SUS-BS_M1_DAMP_T_IN1_DQ (strong)
H1:SUS-BS_M1_DAMP_V_IN1_DQ (strong)
H1:SUS-BS_M1_DAMP_Y_IN1_DQ (strong)
H1:SUS-ITMX_M0_DAMP_R_IN1_DQ (strong)
H1:SUS-ITMX_M0_DAMP_V_IN1_DQ (strong)
H1:SUS-ITMY_L1_WIT_L_DQ (strong)
H1:SUS-ITMY_L1_WIT_P_DQ (strong)
H1:SUS-ITMY_L1_WIT_Y_DQ (strong)
H1:SUS-ITMY_L2_WIT_L_DQ (strong)
H1:SUS-ITMY_L2_WIT_P_DQ (strong)
H1:SUS-ITMY_L2_WIT_Y_DQ (strong)
H1:SUS-MC1_M3_WIT_L_DQ
H1:SUS-MC1_M3_WIT_P_DQ (weak)
H1:SUS-MC2_M1_DAMP_L_IN1_DQ
H1:SUS-MC2_M1_DAMP_T_IN1_DQ
H1:SUS-MC2_M1_DAMP_Y_IN1_DQ
H1:SUS-PR2_M1_DAMP_P_IN1_DQ
H1:SUS-PR2_M1_DAMP_R_IN1_DQ
H1:SUS-PR2_M1_DAMP_V_IN1_DQ
H1:SUS-PR2_M3_WIT_L_DQ
H1:SUS-PR2_M3_WIT_P_DQ (weak)
H1:SUS-PR2_M3_WIT_Y_DQ (weak)
H1:SUS-PR3_M1_DAMP_P_IN1_DQ
H1:SUS-PR3_M1_DAMP_V_IN1_DQ
H1:SUS-PRM_M1_DAMP_L_IN1_DQ (strongest)
H1:SUS-PRM_M1_DAMP_T_IN1_DQ
H1:SUS-PRM_M1_DAMP_Y_IN1_DQ (strong)
soren.schlassa@LIGO.ORG - 23:07, Sunday 25 October 2015 (22825)
The 99.9989Hz comb Keith found (designated H) appears in 109 channels (list is attached). Coherence is uniformly greatest at the ~500Hz harmonic, with many channels approaching .7 and greater, drops off sharply at the ~600Hz and ~700Hz, and is invisible after 700. (See spreadsheet titled "comb_H_sigcohs_wk1.xslx" for a list of cohering channels by line, with coherence value.) 

At all harmonics except the ~300Hz, the structure manifests in the signal and the coherences as two lines .001Hz apart, but if I recall correctly .001Hz is the resolution of the frequency series, so it's safer to say that this is a bulge with .001Hz < width < .002Hz. At ~300Hz, almost all the cohering channels with data in that range show a bulge of width about 0.5Hz (see attached "disjoint_plots" for a comparison of typical channels by harmonic). This bulge, and the fact that it appears in all the same channels associated with the rest of the comb, makes me think that the fundamental may be the bulge at ~300Hz and not the line at 99.9989Hz. An interesting feature of the bulge is that in many cases, it has a prominent upward or downward spike at 299.96Hz, which is just the place the line would be if it were there (see "bulge_w_spike.jpg").

More to come re: changes in week 4 data, patterns in cohering channels, and the spike.
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