Caltech: Zweizig
     Hobart-Smith: Penn
     LHO: D'Ambrosio, Drever, Gustafson, Ito, Landry, Lazzarini, Raab, Rahkola, Schofield, Sigg
     LLO: Chickarmane, Frolov, Gonzalez, Marka
     MIT: Cadonati, Katsavounidis
     Michigan: Riles
     Oregon: Leonor
     Syracuse: Saulson

S1 Roundup: (S1 Web Page )

• Interferometer status (F.Raab, S.Marka)

H1 and H2 science mode livetimes have been 58% and 72%, respectively. There were persistent troubles with H1 in the first week, where sustained locks of 6-8 hours would be interrupted by even more hours of downtime from failure to lock. For unknown reasons, this problem has gone away for now, with an improvement in livetime. There were also some CDS troubles (e.g., necessary reboots) during the first few days.
H2 has been more reliable but much more glitchy than H1, according to various online monitors (but still better than in E7). The IFO is sensitive to seismic noise created by the Hanford vitrification plant, especially to noise spikes occurring about every 24 minutes, thought to be due to a batch plant.

There have been repeated episodes of two different kinds of lock loss:

1. An isolated large seismic event affects one building (end station or mid station) that causes lock loss for the IFO with its end mirror in that building, but not lock loss for the other IFO. The sources of the localized events are not known.
2. A large seismic event near end-Y knocks H1 out of lock, the disturbance propagates down the arm to mid-Y and knocks H2 out of lock six seconds later. Robert and Masahiro have tracked the disturbance down to a water pump turning on. For the remainder of the run that pump will be turned off whenever the Livingston IFO is running.

On Tuesday Dick noticed a "two-thump heartbeat" in H1 with a frequency of 88/min, leading to a comb of 1.47 Hz lines up to about 150 Hz (can go higher if filtering is disabled). This persisted until a small earthquake broke lock and required realignment. Afterward the two thumps became four thumps. The source is unknown. (Note added next day: the owl crew last night tracked down the heartbeat to undamped side motion of the end-X mass modulating optical gain; the motion was originally set off by an Oregon earthquake and has been fixed by turning the servo gain down temporarily and then back up. See elog entry.)

At Livingston, S1 has been coincident with intensive and nearby logging during the day, even on Labor Day, leading to a science mode livetime of about 42%. But at night conditions have been reasonably good. Frequent realignments are required, but otherwise running has become routine, and the L1 spectrum has remained stationary. Reported glitch rates online are low, as for H1.

• Lock Statistics (G.Gonzalez)

In addition to the single-IFO statistics being produced daily by scimons, Gaby has been using a matlab program looking at conlog output to find 2- and 3-IFO coincidence science mode segments and to calculate coincidence livetimes. As of the morning of September 6, the livetimes were L1-H1 (30%),  L1-H2 (34%), H1-H2 (46%), and L1-H1-H2 (24%). The last number can (almost) be compared to 11% for E7, but Gaby has not yet enforced the condition on coincidence segments of being at least 5 minutes long (as is done for single-IFO livetime calculations).
 
• Data Quality (J.Zweizig)

John went over an outline of the Data Quality investigation team plans for producing a more refined set of high-quality database segments. A dedicated DMT monitor called DataQual (based on John's versatile PSLMON programs like RMSBands and ZGlitch) is creating trends of band-limited rms power for four channels per IFO in nearly 40 bands and trends of glitch rates with various thresholds / filtering for about ten channels per IFO. Rauha and Peter Saulson have been looking at selected DataQual power bands and glitch rates for the burst upper limit group and provided sample plots: Rauha(1 23 4); Peter (1 2). John plans to revise the glitch finder to notch out some prominent lines that tend to mask glitches by their non-Gaussian contribution to total RMS (used for thresholding). Looking at trends offline away from the sites is problematic if one doesn't have a local copy of the strictly Sun-platform data viewer. Even there John reports some occasional hiccups in getting data from the network data server.
(KR once again pleaded for a volunteer to write a general-purpose trend viewer for the LSC, one that operates on a linux or generic unix platform. Peter Shawhan first publicized the need for such a viewer two years ago, but no volunteer has yet stepped forward. This would be a very nice, immediately useful tool for a graduate student or postdoc to create for all of us. Interested parties: please see KR.).
Based on what is found in looking at trends, criteria will be set for defining new database segments more restrictive than the nominal "science mode" used in present insertions. If there is a demand, John could also produce customized, more restrictive (or less restrictive) segments for particular analysis groups.Aside from the information provided by DataQual and other DMT monitors, there is also information from the offline DSO's, in particular the burst group DSO's on bottom-line glitch rates. Laura maintains a web page at MIT with compiled results of the burst DSO's (including history plots of rates vs times) which should be quite useful.
 
• Calibration Status (M.Landry)

Calibrations were carried out on H2 and L1 the first evening of the run. Calibrations for H1 had to wait a couple of days because of initial locking troubles. Since then there have been autocalibrations twice per day by operators, the results of which are available on the calibration web page and periodically entered into the elogs at both sites. Click here to see an early comparison by Rana of the three IFO strain curves. Calibration lines have been injected at about 37 Hz and 973 Hz on all three IFO's during the run. There was some confusion initially about the strength of the 973 Hz line, since LineMonitor was having trouble detecting a stable signal strength, but the problem turned out to be in the tracking, not in the line itself, and has now been fixed by Sergey. The last calibration run is planned nominally for Sunday night. Fred suggested that if we were very close but not quite at 100 hours of triple-coincidence data at that time, it would be tempting to postpone the calibration in order to reach the round-number milestone. On Monday night the hardware / software freeze will remain in effect to permit astrophysical injections for the burst, inspiral and stochastic upper limits groups. If necessary/desirable, calibrations could be done the same night.
At the moment, the EPICS alarm that reports the absence of a calibration line from an excitation test point fails to detect an occasional failure mode in which the operator forgets to turn the excitation back on after an autocalibration. Mike suggested it would be more reliable to write a DMT monitor that sets an alarm if the AS_Q power in the expected very narrow band falls below a certain level. There was some discussion of correcting for drifting calibrations due to misalignment. A simple frequency-independent scaling factor based on the strength of one calibration line is not suffficient (in fact, the 37 Hz line has been observed to drift up while 973 Hz falls as alignment degrades). The optical gain contribution to the total closed-loop gain is not flat. Gaby mentioned that she is writing up a note on this subject for the benefit of the upper limits groups. The calibration team hasn't yet confronted this problem, but will be looking at it when time permits after the run. It hasn't been decided yet in what form to provide time-dependent transfer functions.

• Reduced Data Set Generation (I.Leonor)

The RDS generation has run smoothly since the 2nd day of S1. The LDAS CreateRDS command has been used for the generation and seems to work fine. One complication, however, is that version 5 frames are being produced, which cannot be read by any non-LDAS program at the moment. John mentioned that he is trying to link the latest version-5-compatible framecpp library to the DMT and having technical problems that he believes are not fundamental. Once he gets this working, John expects to have two different DMT versions available, one to read/write frame 4 (current standard) and one to read/write frame 5 (LDAS special). Albert reported that it will be a month before version 6 frames will be produced for S1. In principle, programs that link to the latest frame library from Benoit should be able to read those version 6 files. Some online programs (e.g,. the DTT) will not immediately be able to read them, however.
Isabel was asked by Laura to provide to the burst upper limits group a highly stripped-down RDS in frame version 4 of the triple-coincidence playground data (~3 hours) that Gaby and Peter Saulson recently designated. Once that playground set is defined for the whole run, it should amount to about 10 hours of data. Peter agreed to KR's request to query the other upper limits group chairs to see if a coordinated mini-RDS should be created - on condition that Peter be allowed to specify a short deadline for reply.

• S1 Roundtable Discussion (All - Procedures, Investigations, Software problems)

KR solicited suggestions for improving scimon shift procedures and better supporting investigations, along with reports of major software troubles. Summary of issues that were raised:

• Scimons should read e-log entries! (KR agreed to update the scimon guidelines with this explicit directive.)
• More standardized templates are needed for generating status plots (e.g., Rauha's day-by-day DataQual summaries) so that less time is spent creating them and more time studying them.
• Currently outstanding problems should be noted on a whiteboard in the control room so that not every shift transition requires reporting the same 3-day old problem.
• Keeping two IFO's running in good condition at Hanford tended to keep the expert scimon plenty busy, leaving little time to work on the scimon checklist. It might be appropriate to keep two scimons on duty at LHO even when we enter a steady state of one scimon at LLO.
• More systematic and centralized archiving of reference spectra would be useful so that one can easily compare spectra taken at different times. Fred and KR reminded everyone that Tim Olson and his students at Salish-Kootenai College are working on this very project, using a DMT monitor to record spectra and the DTT for retrieving them.
• Peter remarked that the same systematic archiving and retrieval would be desirable for other measures of IFO performance, such as trends of glitch rates.
• Fred raised the issue that we now take a hands-in-pocket approach during data runs. Normally, if the IFO is running reasonably well, we leave it alone, even if alignment is drifting significantly. He wondered if we should instead spend some time each day measuring the parameters of the machine (e.g., closed-loop gains for four main degrees of freedom) so that we avoid major drifts away from the optimum, drifts that lead to difficult lock reacquisition (c.f. problems above with H1 early in S1). A similar issue arises in relieving the DC offsets imposed by the wave front sensing system. The offset corrections are done by hand now, but an automatic script that adjusts biases to agree with WFS values would be preferable.
• Steve reported a chronic problem in using ssh and root graphics together, leading to segmentation faults in the BicoMon monitor. The problem can be avoided by setting xwindows display parameters directly, bypassing the ssh encryption, but Steve wondered if there were a systematic problem with ssh tunneling in the control room. KR and others reported flakiness in tunnel connections between the LHO and LLO control rooms that interfered with displaying LHO and LLO DMT viewer plots simultaneously (e.g., LockLoss status). Daniel ascribed the problem to multiple security firewalls getting in the way.

DMT  Software Status Review:

 
• DMT infrastructure - J. Zweizig

No update - John had to leave early. But see comments above about framecpp and version 5 frames.

• Global summary page(s) - S. Marka

One of the major components of the web-based global status summary page Szabi is working on is a display of up-to-date calibrated spectra from the three interferometers. He now has a prototype of that component working, using the spectra produced periodically by Patrick Sutton's SenseMonitor. At the moment, only the spectrum in the 300-1400 Hz range (used by SenseMonitor for calculating binary inspiral range in kpc) is displayed, and there is no correction for drifts in transfer function. Patrick is working on a post-S1 version that will address both issues.

Updates from DMT monitor authors (updates since August 9 meeting):

• Dave Chin: LockLoss and ServoMon (KR reporting)

There has been some confusion about one entry in the LockLoss livetime summary pages. The total number of hours in lock since the monitor was started is provided, but the wording makes it sound as if the current lock has lasted that long. The wording will be fixed after S1 and a separate entry added with the number of seconds of the current lock. Daniel requested that a table be added showing the lengths of the last ten locks. There is also a new problem with the reading of LockLoss trends which Dave is investigating.
.
• Ed Daw: blrms and PeakMon (no update)

 
• Masahiro Ito: glitchMon

GlitchMon has been running smoothly since the start of S1. No known bugs.

• Sergey Klimenko: LineMonitor and WaveMon (no update)

 
• Szabi Marka: IRIG-B and TimeMon

A bug in the TimeMon code was fixed by Daniel early in S1. There have been some real timing problems reported at LLO recently, requiring cpu reboots. The timing investigation team will be determining at both sites (for the first time) the time offset correction needed to find the correct arrival time of a gravitational wave signal.

• Adrian Ottewill: MTLineMon and CorrMon (no update)

 
• Steve Penn: BicoMon

The GUI interface now informs the user in advance of the time required to compute bicoherence for a given set of requested frequency resolution and time interval. For those wanting mHz resolution, it may be advisable to look back in time at data on disk instead of waiting for real-time data to flow in. Steve has identified some bilinear pathologies which he will be posting on the results page of the bilinear couplings investigation.  He is also looking at ways to further speed up his code, including heterodyning techniques when a user cares only about a limited frequency band.

• Rauha Rahkola:  absGlitch and eqMon

Now that glitchMon has absolute thresholding, the need for absGlitch is not so clear. Rauha urged people to try using glitchMon for absolute thresholding, since it supports more DMT output features and since Masahiro keeps it up-to-date.
 
• Daniel Sigg: MultiVolt (no update)

 
• Patrick Sutton: SenseMonitor and RayleighMonitor (no update)

 
• Natalia Zotov: PTMon (report by e-mail)

Natalia has fixed the trouble she was having in communication between her C++ DMT code and the USGS C code she interfaces to. Her next task is to implement triggers with reasonable threshold settings.
 
• John Zweizig: BitTest, HistCompr, PSLMon , and SegGener (no update but see DataQual discussion above)

• Next  meeting: October 4 telecon at 1:30 p.m. EDT