MMA Imaging and Calibration Group

Date: 6 Aug 2002

Time: 4:00 pm EDT (2:00 pm Socorro, 1:00 pm Tucson)

Phone: (434)296-7082 (CV SoundStation Premier Conference phone 3rd floor).

Past minutes, etc on MMA Imaging and Calibration Division Page
 

Agenda

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News. -Wootten

• It is with deep regret that I announce that Mr. Guillermo Delgado passed away on Friday, 26 July 2002.
    As ALMA engineer and scientist he was responsible for important parts of the ALMA site characterization. Mr. Delgado has contributed significantly to the ALMA site development, such as ALMA radio frequency interference protection and ALMA communication studies. We were all impressed by his enthusiasm and commitment and are grateful for his work at ESO.
    I am sure you feel as deeply affected as I, and that you will join me in expressing our deep sorrow for his family's loss.
    Catherine Cesarsky
   
• JAO News - Telecon 1 Aug
    Configuration Final Review -- Grenoble 30 Sept - 1 Oct 2002.
    Budgets 2003 and beyond due 15 August
   ALMA Site Infrastructure Requirements Review 2002 October 22-24 NRAO Tucson
   ALMA Antenna Transporter Requirements Review 2002 October 22-24 NRAO Tucson
   
• ACC News - Telecon 1 Aug
   EIS submitted 24 July, begin 120 day period
   Meetings in Santiago
   Meeting in Antafagasta
   

Configurations - All

Meetings Past and Future - Wootten

• ASAC Telecon tomorrow--Agenda
   
• Agenda for ASAC Face-to-face. The Charges from the Alma Board are of special interest, here shown with Cox's plan for addressing them. There was an Early Science telecon today to discuss Stephane's draft points.
   
    Early Science Sensitivity Comparisons
    CARMA Sensitivity Comparisons
   Mark says of the site phase stability: I have munged the actual data (for the first two years at Chajnantor, which was an easy to get data set that I use quite often), and the cumulative distributions of the various phase stabilities can be found on my home page
    There is a mighty misconception among almost everyone (which leads me to believe that very few people actually read the literature -- hell, I don't!): while opacity shows a dramatic improvement with site elevation, the phase stability improves much more weakly with site elevation.
    Chajnantor is a great site, but it is far from perfect, and adding the submillimeter bands, which has the effect of snatching up the best phase stability conditions, is pinching is even harder at the other bands.
   Note that tau(225) > 0.2 about 12.3% of the time.
   
• Other Misconceptions
   I don't read Spanish too well, but it seems to me that this article which Peter Gray noted to me attributes ALMA to ESO, a serious misconception! ALMA Antafagasta
• Phase Stability Requirements for Cross Band Observations (ie, Fast Switching) from Mark.
• Although I wasn't completely sure whether 'IPT Lead'=='Project Scientist' I don't think it would work very well if there were a Science IPT Lead who was different from the Project Scientist. Insofar as getting jobs done, I think it works best if PS just keeps us from tripping over each other, doing the same tasks, and gives overall guidance as to what needs to be done next. The NA science group meets every week in telecon, with an agenda (minutes on paper only!) kept at http://www.cv.nrao.edu/~awootten/mmaimcal/ as you probably are already aware. If you would like to be on the NA Science exploder, still anachronistically named mmaimcal, let me know and I'll include you (you can turn mailings on or off, only see digests, or just look at archives if you join). Maybe a few words on plans with 15 August in mind:
    In my mind, that is finishing the configuration ASAP and getting on with calibration, as the telescope on which to test our calibration schemes begins to tower over the desert. Toward this end, Mark will work on total power modeling, finishing his famous unfinished memo on the subject, and Bryan and Steve Myers will guide the calibration group. Steve is working on carrying out benchmarking of AIPS++ using simulated ALMA data right now. Since both of them are at the AOC, they will also help with testing at the ATF. I think that goals should include testing nutation vs. fast switching; amplitude calibration techniques (including, I hope, a secondary calibration system and a semitransparent vane; one on each of the antennas) but not until the antenna evaluation is finished. I would like to see prototype interferometry as soon as practicable after evaluation finishes, in early 2004. I have seen no schedule for the prototype interferometer, nor have I seen the most approximate of milestones for it, and I think this is something the project must quickly and seriously address.
    Mark described a plan in which the secondary calibration system is scrapped. I think this is premature. There is a working prototype, and work is being done on addressing issues Stephane has raised. Some of this will appear in the review of his memo, other material in a memo on further testing. In the best of all possible worlds, ALMA would assign someone to Hat Creek to carry this through to a decision point in 2003. I will propose hiring that person. The problem is that the system is on a specific antenna needed by the array, which is therefore seldom available. The hiree would work to implement an ALMA-appropriate model on the Vertex antenna, should BIMA tests favor further construction of the instrument. I hope that a similar activity will occur in Europe on the semitransparent vane. I had hoped for some GBT-related development of the vane but they have discarded that mechanism as impractical (no people to measure scattering properties of the absorber, etc, etc.).
    The WVR effort is European, but there are working prototypes at the SMA and soon on the VLA, and at OVRO, the latter two at 22 GHz. None produces the calibration correction we need for ALMA. Butler works half time on ALMA and half time on the EVLA, which includes the WVR system. I don't propose money or manpower go into the WVR effort on the NA side, but that we remain close to its progress. IRMA may be deployed at Chajnantor sometime, an NA system. Again, little in the way of money or manpower is devoted to IRMA, but we remain in close touch with its development.
    Site:
   Radford will provide details on this. Fundamentally, data should be collected in support of the ALMA Board request of the ASAC. Milestones:
   1 October 2002: Configuration approved. After this, reconnaissance of the longer baseline locations, with a delta final review after that is accomplished.
   Q2 2003 (1 April?): begin total power tests with evaluated prototype.
   1 May 2004: Prototype interferometer calibration tests? Having seen no milestones, perhaps we can manufacture some.
   1 May 2005: Prototype Band 6 receiver on prototype interferometer? This would press the schedule I noted on a blackboard at the CDL (Having seem no milestones on paper...)
    ************************************************************************
    Ewine's focus:
   --------------
    1. Coordination of European mm astronomers + plans for Euro-RSC, in connection with (but not limited to) EU call for proposals for funding. I'll be working together with Pierre, Peter Shaver and John Richer.
    2. Phase I-> phase II transition in Europe: working together with Dick Kurz + ALMA-E project office on review of European phase I work, procedure for call for phase II proposals and evaluation of those proposals from science perspective
    3. Operations plan: any issues as requested by JAO such as early science operations.
    These three items will likely take all my available time.
   

Calibration--Butler, Mangum

Other

Upcoming Meetings - Wootten

AUG 17/24 URSI General Assembly, Maastricht, the Netherlands Butler attending

AUG 22/28 SPIE Symposium on Astronomical Telescopes and Instrumentation, Waikoloa, Hawaii. Brown, Wootten attending; Text of ALMA article.

SEP 9-13 Winds, Bubbles and Explosions

JAN 5/9, 2003 201st Meeting of the American Astronomical Society

JUL 13-26, 2003 Twenty-Fifth General Assembly of the IAU

JUL 22/25, 2003 IAU Symposium (221): Star Formation at High Angular Resolution, Sydney, Australia. Tyler Bourke is a co-chair of the scientific organizing committee. Good opportunity to show ALMA capabilities.

SEP 22-26, 2003 4th Cologne-Bonn-Zermatt-Symposium on The Dense Interstellar Medium in Galaxies

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Travel

 Oh, always

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