Using the pictures recently taken using the Pcal camera system I have determined the Pcal beam spot position. The numbers quoted below are the Pcal beam offset (in mm) from their nominal position of [0,111.6] for upper beam and [0, -111.6] for lower beam.

LHOX: Upper Beam [1.4+/-0.2, 1.3+/-0.2]

            Lower Beam [-0.4+/-0.3, 1.3+/-0.3]

LHOY: Upper Beam [-0.6+/-0.2, 1.1+/-0.1]

           Lower Beam [-3.1+/-0.1, 1.3+/-0.3]

The pictures for X-end were taken by Travis on 2017/03/28 and the pictures along with the analyzed figures can be found at:

https://svn.ligo.caltech.edu/svn/aligocalibration/trunk/Projects/PhotonCalibrator/Results/pcalImageAnalysis/LHOX/D20170328/

The pictures for Y-end were taken by me on 2017/03/21 and the pictures along with the analyzed figures can be found at:

https://svn.ligo.caltech.edu/svn/aligocalibration/trunk/Projects/PhotonCalibrator/Results/pcalImageAnalysis/LHOY/D20170321/

The last beam spot analysis for Xend can be found at: LHO alog # 29873 and Y-end at: LHO alog # 30105

Krishna, Jeff

There are several recent cases of sudden range drops, coincident with increased quad motion, oplev noise, CAL line upconversion, OMC dither heights and angular motion etc. See Jeff's log for some details and also 34999. It happened again last night on 2017-04-05 from ~05:30 UTC to 06:40 before the earthquake knocked us out. DetChar has suspected ITMY Oplev.

As seen from the previous alogs, it is difficult to follow the causal chain, but I suspect OMC is unlikely to be the problem since it can't influence the QUAD motion which clearly goes up each time. All the QUADs show similar PITCH motion, so it is not clear which was the cause. So far, a smoking gun for the problem seems to be ITMY Oplev YAW 0.3Hz to 1Hz blrms: crossing a threshold of ~0.04 (microrad?) seems to trigger a range drop. Remember that oplevs are used only to damp PITCH motion of the quads but they are independent witnesses in YAW.

I have attached four cases where the ITMY Oplev - YAW sees an increase in the 0.3 to 1 Hz blrms correlated with range drop: April 5, April 2, March 29, March 22. A quick look at the summary pages shows that this increase is only associated with ITMY - Oplev YAW. There are more cases but this is sufficient I think.

It is interesting that even though other Oplevs (such as ETMY) glitch more, it looks like only ITMY-Oplev shows broad low-frequency increase in apparent angular motion.

Edit: For clarification, I think ITMY Oplev sees an apparent increase in PITCH and YAW during these times. Since we use it for damping in PITCH, all QUADS start pitching more affecting DARM. ITMY Oplev may need to be tuned/fixed. The other less likely possibility is that ITMY is rubbing occasionally.

BSC CPS Spectra Notes:   Only item worth noting is that the ITMx V1 spectra is at a higher value overall compared to other ITMx spectra.

HAM CPS Spectra Notes:  Nothing To Note

I've attempted to orient the coordinate system of the ITMX Hartmann sensor relative to the ITM surface. The following analysis suggests that the coordinate system of the Hartmann sensor is flipped horizontally and vertically relative to the ITM, like so:

Determination:

1. The beam splitter baffle earthquake stops (which are at the top of the BS baffle) appear in the bottom of the HWS image (where the vertical pixel indices are low). Therefore, the HWS coordinate system is flipped vertically.
    
2. Next, I used the motion of the CO2 heating beam on the ITM [aLOG 14714] as viewed by the Hartmann sensor to determine the left-right orientation. As the upper periscope mirror of CO2X is actuated, the CO2 heating beam moves across the face of the CP. We observed this with the HWS like so. Decreasing counts horizontally and vertically correspond to increasing values of the HWS coordinates horizontally and vertically.
   
3. That picomotor of CO2X is shown here. There are vertical and horizontal actuators. The pivot point is in the lower left of the mount as viewed here. The decreasing counts on the vertical picomotor correspond to increasing vertical coordinate on the HWS which corresponds to a decreasing position vertically on the ITM, which corresponds to a clockwise rotation of the vertical actuator in this picture. 
   
4. For the YAW (horizontal) picomotor: the decreasing counts correspond to a clockwise rotation which will tilt the mirror to the left in the above image.
5. The CO2 beam inside the vacuum system is folded in the way shown here. When the mirror is tilted to the left the beam tracks to the left across the CP (as viewed from the BS).
   
6. Hence: the left hand side of the CP+ITM corresponds to the right hand side (or increasing horizontal coordinates) of the Hartmann sensor.

Finally, the point absorber appears in the upper right of the HWS coordinate system, so that means the lower left of the ITM (as viewed from the BS).

This Morning noticed that the GWI.stat tool is froze with regards to the Detector states (the time stamp at the top is updating though).  Right now it currently lists H1 & L1 in NOT OK states.

TITLE: 04/05 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 71Mpc
OUTGOING OPERATOR: Cheryl
CURRENT ENVIRONMENT:
    Wind: 14mph Gusts, 10mph 5min avg
    Primary useism: 0.05 μm/s
    Secondary useism: 0.42 μm/s

Winds are inching up to 10mph over the last couple of hours. 
QUICK SUMMARY:

Nicely-running H1 handed off (going on 7+hrs of lock).  L1 was down, but quickly rejoined us.  Nuc5 was rebooted.  Going through Ops Checksheet.

Krishna is here and investigating a range drop from last night before the EQ.

TITLE: 04/05 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Observing at 69Mpc
INCOMING OPERATOR: Corey
SHIFT SUMMARY:
LOG:

• 08:30 - Observe
• added FM6 ITMY ROLL, not yet in guardian, will show in SDF
• 14:23 - a2l
• 14:30 - Apollo to MY
• 14:34 - Observe

STS CENTERING: 2017-04-05 02:03:39.354195

All STSs prrof masses that within healthy range (< 2.0 [V]). Great!

Here's a list of how they're doing just in case you care:
STS A DOF X/U = -0.501 [V]
STS A DOF Y/V = 0.243 [V]
STS A DOF Z/W = -0.639 [V]
STS B DOF X/U = 0.524 [V]
STS B DOF Y/V = 0.316 [V]
STS B DOF Z/W = -0.297 [V]
STS C DOF X/U = 0.361 [V]
STS C DOF Y/V = 0.847 [V]
STS C DOF Z/W = -0.281 [V]
STS EX DOF X/U = 0.081 [V]
STS EX DOF Y/V = 0.613 [V]
STS EX DOF Z/W = 0.066 [V]
STS EY DOF X/U = 0.097 [V]
STS EY DOF Y/V = 0.103 [V]
STS EY DOF Z/W = 0.463 [V]

T240 CENTERING:  2017-04-05 01:56:53.355462

There are 6 T240 proof masses out of range ( > 0.3 [V] )!
ETMX T240 2 DOF X/U = -0.615 [V]
ETMX T240 2 DOF Y/V = -0.708 [V]
ETMX T240 2 DOF Z/W = -0.341 [V]
ETMY T240 3 DOF Z/W = 0.312 [V]
ITMX T240 1 DOF X/U = -0.423 [V]
ITMX T240 3 DOF X/U = -0.385 [V]

All other proof masses are within range ( < 0.3 [V] ):
ETMX T240 1 DOF X/U = 0.057 [V]
ETMX T240 1 DOF Y/V = 0.069 [V]
ETMX T240 1 DOF Z/W = 0.143 [V]
ETMX T240 3 DOF X/U = 0.079 [V]
ETMX T240 3 DOF Y/V = -0.011 [V]
ETMX T240 3 DOF Z/W = 0.052 [V]
ETMY T240 1 DOF X/U = 0.012 [V]
ETMY T240 1 DOF Y/V = -0.02 [V]
ETMY T240 1 DOF Z/W = -0.189 [V]
ETMY T240 2 DOF X/U = 0.18 [V]
ETMY T240 2 DOF Y/V = -0.205 [V]
ETMY T240 2 DOF Z/W = 0.037 [V]
ETMY T240 3 DOF X/U = -0.206 [V]
ETMY T240 3 DOF Y/V = 0.005 [V]
ITMX T240 1 DOF Y/V = -0.167 [V]
ITMX T240 1 DOF Z/W = -0.103 [V]
ITMX T240 2 DOF X/U = -0.11 [V]
ITMX T240 2 DOF Y/V = -0.12 [V]
ITMX T240 2 DOF Z/W = -0.141 [V]
ITMX T240 3 DOF Y/V = -0.101 [V]
ITMX T240 3 DOF Z/W = -0.042 [V]
ITMY T240 1 DOF X/U = 0.024 [V]
ITMY T240 1 DOF Y/V = -0.003 [V]
ITMY T240 1 DOF Z/W = 0.007 [V]
ITMY T240 2 DOF X/U = 0.148 [V]
ITMY T240 2 DOF Y/V = 0.168 [V]
ITMY T240 2 DOF Z/W = 0.063 [V]
ITMY T240 3 DOF X/U = -0.067 [V]
ITMY T240 3 DOF Y/V = 0.091 [V]
ITMY T240 3 DOF Z/W = -0.012 [V]
BS T240 1 DOF X/U = -0.13 [V]
BS T240 1 DOF Y/V = 0.007 [V]
BS T240 1 DOF Z/W = 0.264 [V]
BS T240 2 DOF X/U = 0.109 [V]
BS T240 2 DOF Y/V = 0.241 [V]
BS T240 2 DOF Z/W = 0.031 [V]
BS T240 3 DOF X/U = 0.081 [V]
BS T240 3 DOF Y/V = -0.055 [V]
BS T240 3 DOF Z/W = -0.062 [V]

TITLE: 04/05 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Observing at 67Mpc
OUTGOING OPERATOR: Jim
CURRENT ENVIRONMENT:
    Wind: 4mph Gusts, 3mph 5min avg
    Primary useism: 0.05 μm/s
    Secondary useism: 0.41 μm/s
QUICK SUMMARY:   08:30UTC - in Observe 

TITLE: 04/05 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Earthquake
INCOMING OPERATOR: Cheryl
SHIFT SUMMARY:
LOG:
Recovery from maintenance was painless, for once. We got locked pretty quickly after PCal wrapped up. IFO was locked until just a bit before my shift ended, and an earthquake from Iran arrived. Cheryl is trying to relock now.

I've been looking to see if LHO needs to pursue better L2A de-coupling in the corner station suspensions to improve our wind and earthquake robustness. The good news is I had to look for a while to find a candidate, but I know better what to look for now, so I'll see what else I can find. Looking at a couple of recent earthquakes, I noticed that we seemed to lose lock when the IM4 TRANS qpd pitch hit a threshold of -.6. After talking to Jenne about it, we looked at other QPDs close by and it was immediately obvious that MC2 trans qpd pitch was being driven by MC2 M1 length drive. The attached plot shows the story.

Both plots are time series for and earthquake on March 27 of this year, where we lost lock at around 1174648460 UTC. The top plot shows the MC2_TRANS_PIT_INMON, MC2_M1_DRIVEALIGN_L_OUTMON and MC2_TRANS_SUM_OUT16. The bottom plot is the ITMY STS in the Y direction. The first 600 seconds are before the earthquake arrives and is quiet. The spike in the STS at about 700 seconds is the arrival of the P waves. This causes MC2 sus to  move more, but the MC2 trans sum isn't affected much. At about 900 seconds the R waves arrive and MC2 starts moving more and more, moving the spot on the qpd more and driving down the qpd sum. I've looked at the other pds used for asc and only IM4 trans and MC2 trans seem to move this much during an earthquake.

The interferometer had been locked and we had been observing for about 40 minutes when the TCS_ITMY_CO2 guardian knocked us out of observing. It created 3 diffs in TCSCS, and the ITMY_CO2 guardian complained it was not nominal. We couldn't get back to observing until the guardian had finished FIND_LOCK_POINT and returned to LASER_UP. Verbal has also complained several times that TCSY chill-air is low. I'm assuming for now that this is all related to the TCS work earlier.

TravisS, KarlT, PeterK, RickS

We captured several series of images with the exposure for each successive image about a factor of three higher than the previous image.

Attached are four multi-page .pdf files containing the photos with:

- Resonant Green only (ITM OptLev on)

- Resonant IR and Green (ITM OptLev on)

- Resonant IR at 2W incident (ITM OptLev off)

- Resonant IR at 20W incident (ITM OptLev off)

The camera settings for the images are in the fifth attached .pdf file.

J. Oberling, E. Merilh

This morning we swapped the oplev laser for the ETMy oplev, which has been having issues with glitching.  The swap went smooth with zero issues.  Old laser SN is 130-1, new laser SN is 194-1.  This laser operates at a higher power than the previous laser, so the SUM counts are now ~70k (used to be ~50k); the individual QPD segments are sitting between 16k and 19k counts.  This laser will need a few hours to come to thermal equilibrium, so I will assess whether or not glitching has been improved this afternoon; I will keep the work permit open until this has been done.

For those investigating the possibility of these lasers causing a comb in DARM, the laser was off and the power unplugged for ~11 minutes.  The laser was shut off and unplugged at 16:14 UTC (9:14 PDT); we plugged it back in and turned it on at 16:25 UTC (9:25 PDT).