Caltech: D'Ambrosio,Marka, Zweizig
     Florida: Klimenko
     LHO: Gustafson, Landry, Raab, Sigg
     LLO: Chickarmane, Gonzalez, O'Reilly
     Michigan: Riles
     Oregon: Frey, Leonor, Rahkola
     Penn State: Sutton
     Syracuse: Saulson
 

S1 Reports: (S1 Web Page )

• Calibration Status (G. Gonzalez)

Gaby gave a status report on the effort to track calibration drifts in S1. A simulink model put together by Rana allows prediction of the L1 calibration function for different overall gain factors that vary due to misalignment of the arms or of the recycling cavity. The model includes all known transfer functions that should affect loop gain, including digital filters and agrees well with open loop gain measurements up to about 1 kHz (time delays not included in the model may lead to discrepancies seen there). Efforts to correct open loop gain for observed drifts in detected strength of the injected calibration lines have been reasonably successful, although the signal-to-noise ratio for that detection requires integrations of minutes to achieve good stability. So far studies have been based on measured amplitude response, but it would be desirable and will be pursued soon to monitor the complex response of AS_Q to the excitation channel. Sergey confirmed that LineMon can now provide such info. Calibration drifts are now handled with relative corrections to baseline strengths. Daniel and Fred suggested using absolute strength instead, given knowledge of the transfer function. KR remarked that it would be highly desirable to have well before the S2 run a model for the LHO IFO's similar to what Rana has done for L1 and to have autocalibration scripts working as LLO, as they do already at LHO. Daniel wondered what precision on calibration is needed by the upper limits groups. Gaby reported that the inspiral group needs about 15% precision on amplitude and about 10 degrees in phase near 100 Hz. (KR note: Gaby later gave a LIGO seminar at Caltech on this subject.)

• Results from SenseMonitor (P. Sutton)

Patrick provided a set of plots ( tar ball ) showing calibration-corrected binary inspiral ranges (averaged over orientations). He is now writing up a report, but his preliminary executive summary on the H1 data is in the 235 hours of science mode running, there was an average of 16 kpc for a binary with 1.4 solar mass neutron stars, giving a cumulative integrated volume-time of 4 million kpc³-hours. In determining the calibration line strength for correcting the raw noise-based range, he used a windowed PSD. He was able to perform some consistency checks on his correction algorithm by looking for jumps between inferred transfer functions and daily autocalibration results. Generally, the discontinuities were observed to be small. The frequency range from which the inspiral range is computed is wider than it was online in S1. The lower limit has been lowered from 300 Hz to 20 Hz. KR asked Patrick to doublecheck how much the range increases with the frequency range change, since the rescaling algorithm used here isn't expected to work well below 100-200 Hz. Patrick will soon be looking at L1 data from S1 and will set up a web page with a summary of results.


• Data Quality (J. Zweizig)
  
  John gave a followup report on what he presented on October 4. He hasn't yet finished rerunning the data quality monitor on all the data, for technical reasons, but he has written a preliminary draft summary based on what he has seen so far. Briefly, he finds a number of potentially important pathologies: 
• Periodic noise bursts in the 39-56 Hz band of H1 AS_Q correlated with similar bursts in REFL_I. These bursts occur roughly every 20 minutes and may be connected with automated discrete actions in the PSL control system. Fred suggested looking at PSL EPICS channels for source glitches. 
• A 100 Hz "bulge" in H1 AS_Q on August 26 (blrms increased 2 orders of magnitude for more than 2 hours). A similar bulge was seen briefly again on August 27.
• Occasional H2 lock stretches with anomalously high glitch rates, mostly seen in REFL_I
• Periodic glitches in L1 MC_F in 150-261 Hz range, correlated with glitches in REFL_I

John is creating new trend data from the data quality monitor and will eventually replace those now at the site (generated online during S1) with the revised versions. In order to allow different upper limits analysis groups to define their own "good data" criteria, John plans to set up software infrastructure for choosing among candidate veto criteria determined from these studies.

• Fred expressed concerned that more configuration control be put in place on trends produced by DMT monitors, given the snafu in S1 when one monitor's trend channels were renamed, leading to malfunction of one of the frame builders. John offered to compile a list of all known DMT trend channels to serve as a baseline.
• Next  meeting: November 8 telecon at 1:30 p.m. EDT. Schedule for S1 investigation reports over next several meetings