AEI-Potsdam: Sintes
     Caltech: Lazzarini, Shawhan, Zweizig
     Dublin: Ottewill
     Florida: Klimenko
     Hanford: Raab,  Sigg
     Michigan: Riles
     MIT: Daw
     Oregon: Mauceli, Strom
     Penn State: Finn, Mohanty, Siddiqui
     Syracuse: Penn

Data Monitor Tool Status (John Zweizig):

• John is working on the next release of the DMT (new features described in last teleconference).
• Interested users can get a preview of the new release on the Hanford sand machine in the directory ~dmt/new and can link to it by setting the environment variable DMTVERSION=new (instead of the normal 'pro' value).
• The new release represents an extensive change from the January release (1.1B) and debugging is not quite complete. At the moment, John is improving the message passing interface and the trigger manager/client communication. The display manager will not be ready for this release, but a hook for it is in place.
• Code contributed by Adrian Ottewill (line tracking) and Teviet Creighton (IIR filter generation) have not yet been incorporated. The code from Teviet is an extracted subset of the LAL library with a wrapper. John will complete the merging of the code into the DMT.
• John will be at Hanford June 4-9 and generally available at 509-372-8300 (x195).

• Line noise:

 
• B. Allen, A. Ottewill (Adrian reporting)

The line tracking code was sent to John in April (see above and minutes of last teleconference). Adrian has mainly worked recently on inter-channel correlations (see below).
• S. Klimenko

Only small changes have been made to line tracking code since the last teleconference. Sergey has mainly worked on data compression code recently (see below). He asked how best to allow users to specify lines to be tracked. It was suggested that he write a config file reader. He will do so and give his complete code to John soon.
• A. Sintes

Code for removing 60 Hz lines and harmonics has been converted from Matlab to LAL C code. Again, it was suggested that a config file reader be provided (Peter Shawhan requested that config files be placed in a default directory to allow easy restart of monitoring processes. John is considering writing a standardized config file interface.)
John has agreed to write a wrapper for the LAL code. Some discussion ensued on whether it was wise for the DMT to support direct linking to LAL libraries, as opposed to incorporating source code subsets. John would like to gain more experience in LAL incorporation before a decision is made. KR expressed concern that DMT releases not be tied to LAL releases. John mentioned he had head that the LAL code uses unix signals for error handling, which would be undesirable in the DMT environment. Sam Finn volunteered to check this out.
• Characterizing seismic noise:

 
• E. Daw

A  seismic monitor has been running continuously at Livingston since April 19. It monitors (every 16 seconds) the power in two frequency bands: 0-1 Hz and 1-5 Hz and records to a disk file. Before sending this code to John, Ed plans to incorporate IIR filters instead of the FIR filters used now, in order to obtain sharper corners on the filters. He will look into using Teviet Creighton's code of which he was unaware before this meeting. He asked whether he should focus on the seismic monitor task or the general-purpose band-limited rms moniotr task (below). He was encouraged to give higher priority to the latter, and to gain more experience with real-data seismic monitoring before releasing a "standard" seismic monitor.

He stated that it would be important to store seismic data permanently and wondered how best to do so, which provoked a more general discussion on storing periodically recorded detector characterization information. Daniel Sigg pointed out that it will soon be possible to generate framed second- and minute-trend data outside of the DAQ system and suggested that trend files would be a natural place for regularly recorded performance characterization information, as opposed to making regular entries in the meta-database. Peter, who strongly agreed, said that the meta-database was more natural for hourly updates and, of course, transient triggers. He pointed out that although trend data is stored in the CACR archive, there exist no tools yet for accessing it. Such tools do exist now for trend data stored on site. No objections were raised to Daniel's proposal.
 

• Inter-channel correlations:

• B. Allen, A. Ottewill (Adrian reporting)

Adrian had planned to release his code by today, but a last-minute check of the code on 1994 40-meter data turned up a segmentation violation deep in the DMT infrastructure code, which he hasn't tracked down. He and John will talk offline to sort this out. It may be related to the fact that the old data's frame time interval wasn't a power of two times the time sampling bin. Once this technical problem is sorted out, Adrian will give the code to John.
• Bilinear cross-couplings

 
• S. Penn

Although he hasn't had much time to work on this task in the last month, Steve still plans to have at least preliminary code ready in a month, based on the analysis techniques described by Albert Lazzarini at the March LSC meeting.
• Operational state:

 
• R. Gustafson, K. Riles (KR reporting)

KR had planned to give the complete code to John by today, but didn't quite make it. The essential code is written, however, and runnable on the Hanford sand machine (look in ~keithr/osc to find a code snapshot, sample program and makefile). Remaining work to be done before giving to John: support of config/log files, cleanup of input/output, automatic booking of daq channels used in state definitions, and fleshing out of documentation. This should be ready for John next week.

• Bandlimited RMS

 
• E. Daw (see above)

 
• Time / Frequency plots
• (see Mohanty talk below)

 
• Non-Gaussian noise

 
• S. Finn, S. Siddiqui

Sharif has installed the DMT at Penn State and is working with Soumya on conversion of existing power spectral density transient detection code to the DMT. The same infrastructure can be used to convert code for quantifying non-Gaussian noise. Sam offered to provide that information in a DMT monitor.

• Power spectral transients:

 
• S. Mohanty, S. Siddiqui

As discussed at the last teleconference, this task has been broken into two stages: 1) providing a general-purpose tool for monitoring & displaying power deviations from the average in frequency bands vs time and 2) using pattern recognition to detect and record statistically significant transients. Sharif has run into a technical problem in creating displayable images, but was given several suggestions on persons to contact. Once this is sorted out, the first package will be given to John. It will include a graphical display to serve as a general-purpose time/frequency plot (see above).
Fred Raab asked John how long it would take for the code to be incorporated into the DMT release. A summer student is arriving Monday at Hanford to start testing out DMT code. It was suggested that Soumya get the existing code running soon on his account at Hanford so that the student need not wait for the next DMT release.  Sam offered to make this a top priority of the Penn State group and hoped to have the code available for trial early next week.
• Servo instability:

 
R. Gustafson, K. Riles (KR reporting)
Nothing new to report since the last teleconference. This code should be ready in early to mid July, perhaps before the next teleconference.
• Event catalog:

 
• J. Sylvestre, R. Weiss (KR reported on behalf of Sylvestre who was out of the country)

There have been no changes to the core program since the last teleconference, but some testing has been done with white noise and chirp signals. A summer student, Olivier D'Arcy, is developing a GUI in root for the monitor which includes a data viewer and control panel. The viewer could, in principle, be adapted for use with other DMT monitors. A filter bank to detect overhead airplanes (see Julien's analysis of the engineering run data)  will be generated and included in the first release on June 15. Julien will be at Hanford June 19-23 to install the program and show interested physicists how to use it.

• Flickering optical modes:

 
No volunteer!!!
• Transient detection using adaptive denoising methods

 
• E. Chassande-Mottin (no report)

This task has a milestone of October 1.
• Impulse recognition:

 
• Although no one has volunteered for this task, it has much in common with the matched filtering technique used in the event catalog (see Sylvestre report above). Determining the appropriate filters to use to recognize impulses needs work. A volunteer is welcome!

 
• Magnetic field transients

 
• E. Mauceli

A basic version of the code is now running at Hanford and has detected the periodic current draw of dust monitors. Since Evan is also planning to write some priority 3 transient monitors (quakes, wind gusts, etc), he has decided to revamp substantially the structure of his code to be more object-oriented, giving more flexibility for defining monitoring parameters. He hopes to have this complete in two weeks and certainly by the next teleconference.

Status report on Data Set Reduction: D. Strom

• David began by giving the floor to Sergey who reported on recent work in data compression.
• Sergey has investigated both lossless and lossy compression. His own data compressor is based on wavelet decomposition, but he has also investigated other available packages, including gzip, arj and eri for lossless compression and mpeg3 (designed for audio channels) for lossy compression.
• As a test, he has tried compressing 10 16-KHz channels from the April engineering run. He finds a lossless compression factor of 2.05 using simple differentiation followed by gzip and a factor of 2.40 using a technique he calles Random Signal Generation (RSC - that exploits the nearly Gaussian behavior of the signals) followed by wavelet transforms. The second technique is also 5-8 times faster than the first.
• He has also tested and quantified the energy loss in using mpeg3 and a  dynamic range reduction technique (integer trucation after a scale factor division, but applied to the wavelet transforms). He finds comparable performance. For example, both can give roughly five times compression, with about 1% energy loss.
• To proceed further, he needs guidance on defining a benchmark for compression performance, e.g. minimum acceptable energy loss for given compression factor.
• A discussion ensued on how to go about defining benchmarks that aren't arbitrary. In the end, David agreed to propose a small set of specific benchmark tests (e.g., line removal and regression performance for original vs compressed data), but it was also  decided that the group as a whole should help out in this effort. In particular, toward the end of the summer, the data set reduction subgroup will provide a sample of compressed real data (most likely from the April engineering run). Persons working on DMT algorithms will then be asked to run them on both the original and compressed samples and to report back on any differences found.
• David also reported on other data reduction work. He expects a DMT data decimation routine to be ready by August 1, compatible with having a standardized sample of reduced data by summer's end.

Time Dependence of length control calibration in April engineering run (6/14/00 revision) : P. Shawhan

• Peter has tried reproducing offline the calibrations done online every four hours during the April engineering run, in order to investigate observed time dependence of the calibration constants.
• The calibrations were based on several-minute dithers of the input mass position at 30, 300 and 1000 Hz. He derives  a new calibration every minute from the ratio of length control signal power spectrum bin to the dither amplitude. (This analysis was done on the Hanford fortress machine using the Diagnostic Test Tool (DTT).) A correction was made for baseline noise in the spectrum, using adjacent frequency bins.
• His goal was to determine whether the long-term calibration changes observed were due to real long-term drifts or due to intrinsic spread in the calibration, hence the 1-minute intervals for repeating the calibrations.
• More fluctuation (few %) was observed on short time scales than expected. Although he hasn't quantified the statistical error on each measurement, Peter believes it is much smaller than the spread observed, suggesting a systematic fluctuation. (see June 14 revision of note above for supporting evidence)
• During two calibration periods observed, the arm lost lock and regained it. In one case, the calibrations showed pronounced drifts just before the lock loss. In the other case there was no apparent warning.
• One calibration was done during a period immediately following lock reacquisition when alignment servo gains are automatically adjusted. The derived calibrations show large deviations from nominal values, indicating large sensitivity to the machine's alignment state.
• As a cross check, the shadow sensor signals from the end mass were checked for stability. Except for the one calibration during auto-alignment, the end masses were indeed stable.

• A teleconference of eight persons was held a week ago to hash out issues and put together a rough plan for integrating detector characterization into upcoming LDAS Mock Data Challenges. (MDC's).
• It was agreed not to try this integration in the first MDC scheduled for the end of July to test the data conditioning API. Instead it was proposed to plan on one or more followup "mini-MDC's", since at least one will be needed to test the frame-reading API, anyway.
• Ideally, there would be one such followup in early November to test 1) frame reading, 2) time interval vetoes, 3) line removal and 4) regression correction. It should be noted, however, that no one has volunteered to lead this followup MDC. (KR and Kent Blackburn hope to persuade Sam Finn to take this on, since he is leading the first MDC.)
• An important technical note is the agreement reached to derive and use line removal and regression coefficients in the data conditioning API, not to derive them in the DMT for downstream use in the API. Since we want essentially the same code to be running in the DMT, however, for diagnostic feedback, it was decided and John agreed that the DMT will fully support the data structures used in the data conditioning API. This will allow code to be written for both environments with minimal variation. It is assumed, though, that monitor parameters would be quite different for the two environments.
• Adrian, Sergey, and Evan have all volunteered to help in this MDC. The next teleconference of participants will be June 23.
• Peter had pointed out at last week's meeting that we are evolving toward an arrangement where it will be difficult to reproduce detector characterization algorithms as part of astrophysics analysis, since those analyses must follow the C-only LAL specification, while both the DMT and data conditioning code are written in C++.
• Sam raised the possibility that a hook could be inserted into LAL routines that allows for a C++ call. There is already a hook for any necessary additional data conditioning. He will raise this issue with Kent Blackburn.
• It was pointed out that if detector characterization or data conditioning had to be repeated / improved offline, there should be no fundamental reason it couldn't be done on a stand-alone node of an analysis Beowulf system before being shipped to LAL code for examination.

A.O.B.

• John mentioned that he has rerun his trigger generation code (see minutes of last teleconference) on the April engineering run data and that it would be possible to run other monitor triggers on that data in the near future, as a test. After some discussion, it was decided to plan on running such a joint test in mid to late July, after more transient analysis code becomes available. The existing entries in the meta-database will be wiped to be superseded by the new set.
• Next teleconference: Friday July 7 at 11:00 a.m. EDT (8:00 PDT).