Contact Information Agenda/Minutes for meeting Tuesday, 3 January at 4:00 pm EDT.

Date: 3 January 2006 held 17 Jan

Time: 4:00 pm EST (6:00 pm Santiago; 2:00 pm Socorro, 2:00 pm Tucson)

Phone: Phone: (434)296-7082 (CV SoundStation Premier Conference phone 3rd floor). No Video planned.

Past minutes, etc on MMA Imaging and Calibration Division Page


  • Cost Review - The Delta CR and the NA CR dates are set and wheels are in motion. Risk Register
  • ASAC Meeting - The ASAC has a charge: Review the existing analysis fo the polarization and mosaicing performance of the hybrid ALMA array and consider the priority and timescale for further analysis by the Science IPT. What do we have?
    • Design and rotational stiffness of the AEM quadripod. According to SS, this will be addressed but for now assume the quadripod is as on the AEC antenna. Gist of discussion--we will measure the beams on the prototype antennas at the ATF and then on the production antennas at the OSF/AOS. To best understand the results, they should be compared to calculations. The calculations might best be done with software such as GRASP8. Ideally, the antenna IPT will do this but it is not known to be in their SoW. Leave this on hold for now.
  • Science Requirements -- The revised document is located in the Science area.
    • Master Frequency Standard (MFS): there are two alternative Rubidium Oscillator Options available. The options are identical in terms of stability i.e. Frequency/Timing Allan Std deviation for time intervals up to 24 hrs. However, the options are very different in terms of drift rate per month (720 hrs) - 1 or 5 times 1E-11 - and the prices differ also. Recommendation: IF JP to provide H maser, go with cheaper one. If JP not to provide H maser, to with expensive one and cheaper one as backup. Need to understand the timescale for the possible JP maser. Probably need one 'expensive' and one 'cheap' Rubidium standard, the latter as a backup spare, as this is a single point failure for ALMA.
    • Subarrays:
      • Implement at least one hour of continuous reset-free dynamic range on the LO reference. This is driven primarily by the baseline calibration mode which can take 30-60 minutes. Shillue notes: It is clear that the primary contributor is the fiber run up the telescope. The temperature distribution under worst case conditions on this fiber will determine how we design the LLC, and how complex and costly the stretcher is. In yesterday's first cut, I basically assumed that the fiber going up the antenna was exposed to ambient outdoor air. ALMA memo 540 shows that the 1-hour outdor temp change at Pampa la Bola rarely exceeds 20 deg pk-pk. One might suppoose this is too conservative because the fiber run is in a mostly enclosed environment. On the other hand, radiant heating of the pedestal walls may create an oven effect over 1-hour time scales during the early AM and late afternoon diurnals. I have made inquiry with the EVLA RT-phase group to see if they have any empirical data. MAybe someone else has ALMA ATF data or data from some other antennas that can help me? Angel has access to the internal and external air temperatures. He can calculate the temperature offset (inside v/s outside conditions) and the damping factor in the temperature tendency inside the antenna due to the thermal insulation. Angel will do the temperature calculation. Perhaps APEX has similar information, for the actual site. See email from Larry and Shillue sent during telecon.
      • Number of subarrays: A misinterpretation of the BCP to cut subarrays to two is that the final four needed can comprise the two we have after the cut plus two from the ACA. This is not correct. The ASAC and the Board exhorted the project to implement the additional subarrays to bring the bilateral array complement to four asap. Al believes this should be accomplished by mid-2010. Comments? No comments, no disagreement heard.
  • Characterization -- de Breuck is new APEX PS and may be able to help. NB No news on new road or fiber routings from Beasley; Al to investigate.
  • NAASC news -- Hibbard
    • Calgary Special Session for ALMA approved. Talks by Turner, Johnstone and Blain. C. Wilson giving general invited talk.


  • Homework from previous IPT meetings:
    1. Two-antenna document. Working doc distributed; IPT leads/deputies to jointly fill out, return by Nov 5th. (ESO has done some Exec-based analysis).

Science Corner:


Official JAO Calendar New!!

Events of Interest

(see also Al's ALMA Biweekly Calendar)

Day Date Time (EST) Event location details
Dec 22
ALMA Board telecon
Jan 9
ALMA Town Meeting
Jan 26
ALMA Board telecon
Jan 26-7
all day
ALMA Delta Cost Review
Jan 30-2Feb
all day
ALMA NA Review
Feb 23
ALMA Board telecon
22-24 March
all day
ALMA Board Meeting
13-14 June 2006
all day
ALMA Board Meeting
9-10 November 2006
all day
ALMA Board Meeting

Upcoming Meetings

"IR Diagnostics of Galaxy Evolution". 14-16 November 2005, Pasadena, CA

Physique stellaire avec ALMA November 14/15, 2005, GRAAL - Montpellier.

Latin American IAU Regional Meeting 12-16 December, Pucon, Chile

National Radio Science Meeting 4-7 January, Boulder, Colorado

American Astronomical Society 9 Jan 2006 ALMA Town Meeting, Washington, D. C.

From ZMachines to ALMA 13-14 January, Charlottesville, VA

ASTROBIOLOGY SCIENCE CONVENTION (AbSciCon) 2006 2006 March 26--30 in Washington, D.C.

Complex Molecules in Space: present status and prospects with ALMA May 7 to 11, 2006, Fuglsoecentret, near Aarhus, Denmark

SPIE 24-31 May, Orlando, Florida

50th anniversary of the founding of NRAO October 15-19, 2006; Charlottesville, Virginia

Science with the Atacama Large Millimeter Array (ALMA) II November 13-16; Madrid, Spain

See also NAASC listing

-- AlWootten - 28 Dec 2005
Topic revision: r3 - 2006-01-17, AlWootten
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