Draft Minutes of 2003-09-10 NRAO AIPS++ Users Group Meeting Date: 2003-9-10 (Wednesday) Time: 1300 MDT Video Hub: CV-conf Rooms: SOC317/CV311/GB241/TUCN505 AIPS++ Threat Level is: Yellow = Elevated [We have some breathing space, but the pressure is on.] Agenda: 1. NAUG News o The highest priority is for pre-testing of ALMA deliverables for Release 1.0 (Oct03). An action item for Joe and me is to get the testing targets for September ready asap. *Action Item: There are some things ready to test and we (Joe and Steve) will get these to testers when Steve returns from GB. Testing plan is in development. Work being done to coordinate with the January integrated ALMA testing (Debra). 2. AIPS++/ISD Status Report (Joe) o Benchmarking - the target is to be within a factor of 2 of equivalent packages (AIPS & GILDAS) by R1.1. Sanjay, George, Kumar and the team have been making good progress. Even more improvements have been made since last meeting, see the ASAC report below. A new document will be available for the current stable describing the changes. o Discussions have continued with the former consortium partner ATNF regarding mutual development of AIPS++. We are close to an agreement. MOU draft has been undergoing iteration. Telecon with NRAO director indicated that the observatory is interested in this type of collaboration. Bryan asked about ASTRON involvement. Joe responded that Jan Noordam was still working on this but had not had confirmation from the higher ups at ASTRON. o The new stable snapshot is v1.9 Build 075, see http://aips2.nrao.edu/docs/reference/updates.html (Note - we have uprev'd from 1.8 to 1.9.) There is also a recent stable version v1.9 Build 103. We have *four* builds now available for testers/development. The stable snapshot releases can be accessed via: /aips++/stable_ss1/ while the intermediate stables (less project level testing has been performed on these) is in /aips++/stable 3. ALMA (Kumar, Joe, Debra, Brian) o The ALMA Science Advisory Committee (ASAC) was held this past weekend in Hamilton, Ontario with Debra and Brian attending. We will try to get a report from them on the happenings there and at the ANASAC held earlier. By all accounts, our performance improvements have been very well recieved even by the AIPS++ skeptics, and also it looks like we wont have to hit a moving target this year, so the team can get back to development soon. I attach Debra's preliminary report on this: http://www.aoc.nrao.edu/~smyers/aips++/reports/dshepherd-ASAC-sep03.pdf George asked about interim feedback on progress for CDR2 - what are the key measures? Debra responded that there will be another ASAC meeting in February - it still isn't clear who will need to be present (i.e., Brian or Debra). The measures for CDR2 are the benchmarking, CDR1 committments, prototype pipeline and the testing reports. The NAUG's pre-testing is critical. Debra is keeping Lee Mundy and Leonardo Testi up to date on progress (the ALMA reps for this). 4. EVLA (George, Steve, Joe) o The EVLA Advisory Committee meeting was held this Monday/Tuesday Sep 8-9 in Socorro, Joe and Bryan will summarize the deliberations there. Joe presented the AIPS++ reorganization and development plans (e.g. ALMA driven development) there. Joe discussed this first. Overall, it seems that the progress being made is viewed favorably. There continues to be skepticism particularly on the part of the ACM chair (Mark Reid), however, based on the exit interviews, there will be an adequately favorable report to continue work without further disruption. Bryan and Frazer made the additional comments that it was important to convince the committee that it was okay to have the current ALMA focus but it was important not to lose site of EVLA-specific needs- in particular, the worry was that AIPS++ could 'pass' for ALMA but still 'fail' for the EVLA. It was also advised to wait for the report since the exit interviews can sometimes be quite different than the written report. In addition, Bryan stated that he does need to think about what the contingency is for the EVLA if AIPS++ is not accepted. Joe expressed some concern that such thinking could distract the effort to make AIPS++ work; Bryan made it clear that the 'best' course was still to make AIPS++ successful. Frazer(?) also commented that it was also clear from the advisory committee that they are very interested in seeing the Phase II proposal move ahead. 5. Main Event - Presentations and Discussion Items Demo: Viewer Blinking (King) David gave an excellent demo of the existing prototype. Some issues/enhancements raised during the demo . 1) minor: for multiple image displays, highlight the tracking bar information. 2) major: currently, the blinking doesn't accomodate blinking between different planes of images, i.e., you can't directly compare plane 12 from one image and plane 14 from another image. This is a necessary function for blinking. 3) would like the ability to have the spectral display from multiple images appear on the same plot (slaved together). 4) would like transparancy in the viewer for overlaying images. Discussion: o FFTs in AIPS++ - Sanjay will lead a discussion of an issue regarding FFTs for imaging. In particular "With current changes, the AIPS++ CS-Clean is less than a factor of 2 slower than AIPS. The difference now is largely coming from our use of full polarization formulation of the emission which requires use of Complex->Complex FFTs at places where a specialization can use Real->Complex FFTs. Whether we want to make this specialization now is a scientific discussion and needs to be discussed more seriously." Fred Schwab discussed this in detail with Sanjay. The key aspects are that AIPS uses the compact (R->C) form for speed and size issues. The performance gain of using this in AIPS++ will not be a factor of 2 since the FFTs are not the dominant performance computation. There are science cases that will use the full Complex->Complex (George pointed out VSOP observations). Overall, the conclusion was to retain the existing AIPS++ technique. o Upcoming discussion items: - Imager performance improvements - Visualization (Brisken, 24Sep?) 6. AIPS++ Developments (Joe, Kumar, George, David, Sanjay) o Project Office - see latest targets and info at: http://projectoffice.aips2.nrao.edu/ o Specific development items (from minutes of last 2 meetings): *Viewer - Dave King has added more MS editing functionality, such as statistical editing (RMS, deviation vs. mean), zoom fixes, and prototype image blinking. See the viewer docs for viewerdisplaypanel option records: http://aips2.nrao.edu/docs/user/Display/node182.html e.g. under "MS and Visibility selection" for RMS and running mean difference. Blinking demo was completed, and a usable version is forthcoming shortly. *uv-plane continuum subtraction (ms.uvlsf) - George has checked in this new function. See the daily URM entry for ms.uvlsf, currently http://aips2.nrao.edu/daily/docs/user/General/node355.html *image-plane continuum subtraction (image.continuumsub) - George has checked this in, see the daily URM entry for image.continuumsub, currently http://aips2.nrao.edu/daily/docs/user/General/node44.html *calibrater scan-based time gridding (calibrater.setsolve) - George has added this capability to calibrater, along with some critical performance improvements. From the URM: "The solution interval t, if > 0.0, specifies the duration of data used for each calibration solution. In general, the solution intervals are measured from the beginning of data segments for each field and spectral window. If t is large enough, a single solution may encompass data from more than one scan (as long as the field and spectral window are the same). The solution interval represents a coherence time, not an integration time w.r.t. gaps in the time series; in effect, such gaps are ignored, and the lastest time in the solution is never more than t seconds after the earliest time. If t = 0.0, one solution per scan will be performed and delivered, regardless of the (variable) scan durations." See the daily URM entry for calibrater.setsolve, currently http://aips2.nrao.edu/daily/docs/user/SynthesisRef/node24.html Comments on any of these are welcome. 7. Upcoming meetings and deadlines: o 2003 Oct 1 ALMA Release 1.0 o 2004 Apr 1 ALMA Release 1.1 o 2004 Jun 1 ALMA CDR2 = Judgement Day! The agendas for past NAUG meetings are archived at: http://www.aoc.nrao.edu/~smyers/aips++/agenda/ The minutes for past NAUG meetings are archived at: http://www.aoc.nrao.edu/~smyers/aips++/minutes/