ALMA previous meeting    

Contact Information

  • 2010-9-15 15:30 UT
    Note 'unusual' UT time.

  • Note: C. Wilson points out line noise may be muted by pressing *6 which works thru the call center.
  • Duration: 1 hr
  • Toll Number: 1-203-480-8549
  • USA Toll Free Number: 866-600-8836
  • Passcode: 3283890
  • Leader: Hills, Wootten, Testi, Saito
  • Attendees:


1 Old Business The enhanced Agenda from the last meeting is available. Science IPT notes from the last telecon are not available.

Seven at the AOS

Seven ALMA antennas in operation at the AOS, seen in this photo of unknown provenance 2010 August 10. There are a different seven there now; kudos to the person who can identify all correctly.

See other images and animations.

  1. New Business--Project news/updates.(Hills, Peck)
    • For a recent summary see July 2010 Science report.
    • Previous reports for the project as a whole are at ALMA Monthly Reports.
    • See : Science_Milestones_31Aug2010.pdf: Science Miletsones 31 Aug update for 'the big picture'. Infrastructure instability continues but seems to be improving.
    • As seen above, seven antennas were available after a move of DV07 to the AOS at pad T701. The array now consists of DV02 in pad J504; PM02 in pad T701; DV03 in pad N605; DV04 in pad T702; DV05 in pad J505; DV06 in pad T704; DV07 in pad J510. We are calling this the "Initial Commissioning Array" configuration. This allows good tests of e.g. antenna performance at different elevations. We expect to have 8 antennas later in September.
    • We have recently sent this note round to the Board and Advisory committees as a morale booster. ALMA Test data. NGC 253. If you want to show these in meetings and the like that is fine, but please remember that these are NOT "ALMA images". This is just "test data", "test results" or at most "test images". Please do not leave these images with people at this point. If the talks from a meeting are put on a web site, please remove the "test images" first.
  2. Change Requests and other technical items.
    • 258. Comments are available at the link from CRE 258. See also discussion at CSV-463. Change Several Requirements Applied to the Back End Antenna Article CRE Number : ALMA- Summary:
      • a) Change the requirement for VSWR from ≤ 1.4 to ≤ 1.8 in Section 3.1.1 of the ICD between the Front End and Back End IF Processor (ALMA-
      • b) Change requirement 272 from ≤ 3 dB to ≤ 4.9 dB gain variation (pk-pk) across a baseband channel (2 - 4 GHz) allocated to Back End (Antenna Article) in ALMA System Technical Requirements for the 12m Array (ALMA- Also change the passband gain variation requirement 02720 in Technical Requirements for the Back End Subsystem (ALMA- allocated to the IF Processor (IFP) from ≤ 2.7 dB pk-pk to ≤ 3.7 dB pk-pk and allocated to the Data Transmitter (DTX) (digitizer) from ≤ 1 dB pk-pk to ≤ 1.2 dB pk-pk.
    • CRE 254. Change Request for Band 1 Phase Noise CRE Number : ALMA-
      • Description : Change of the ALMA Specification for Band 1 Phase Noise. The System Technical Requirements and BE Technical Requirements specify a maximum 1st LO Phase Noise of 53 fsec for all ALMA bands. There is an allocation of 38 fsec for the Backend contribution, which is measurable at the output of the Laser Synthesizer. This change implements an exception for Band 1, with an allocation of 80 fsec for the BE contribution, keeping 38 fsec for the FE contribution. Thus there is a new total for Band 1 of 88 fsec from the 1st LO and 96 fsec for the electronics.
      • No serious issues.
    • Source on Chajnantor. Here is a draft note on the requirements for an Artificial Source to do holography and polarization calibration measurements. This has been talked about for some time but interest has been renewed as a result of the investigations of the surface errors on the Vertex dishes. (See slides). The origin of the problem has been found - damaged clamping devices in the course adjustment - and the obvious problems on DV01 have been corrected. To know what to do about the other antennas we need to do a lot more high-resolution holography at the high site. This source is proposed as a way of making this practical using the astronomical receivers. The holography side is straight-forward but we need help in understanding the polarization requirements.
  3. Employment
    • JAO DSO Support Astronomer positions. Proposal Handling Team Lead interviews scheduled.
    • ESO:
    • NRAO: Stuartt Corder, Jim Braatz to join NAASC team.
    • NAOJ
  4. Astronomer Outreach: ALMA News. JAO ALMA Webpages. JAONewsletter No 6. NRAO eNews ESO Newsletter No 16 NAOJ News. NRAO ALMA Calendar
  5. Current SYSE- ALMA System Diagram Rev Q
    1. Current IPS attached
  6. Directories

Project Scientists

  1. North America
    • The Panel Reports from 'New Worlds, New Horizons in Astronomy and Astrophysics' including the Radio Millimeter Submillimeter (RMS) report, was issued at the end of August.
      • Report of the Panel on Radio, Millimeter, and Submillimeter Astronomy from the Ground
        • ALMA Development: The consortium plans a program costing $90 million over a decade, of which $30 million would come from the North American partners. The panel fully supports this plan.
        • Specific mention of new receiver bands, mm VLBI. * ANASAC f2f meeting 13-14 September.
  2. Europe
  3. East Asia
  4. ASAC Report, Board Meeting
    • Next meeting 13 October

Jeff Mangum -- Calibration

Bojan Nikolic/John Richer -- WVRs

  • Temperature profiler for ALMA based on radiometric sounding of the O2 lines has arrived and is now being commissioned. The sounder is currently at the AOS, on a temporary location very near the Technical Building. It is already continuously taking data and is undergoing testing. Current work is design and implementation of final software interfaces

  • O2 sounder at the AOS with antennas in the distance:

Lars-Ake Nyman -- eSSR

  • Second set of end-to-end testing in Aug/Sept: CfP? to archive

Wootten -- Site Characterization

  1. Status of phase monitoring interferometer.
    • Discussion document draft on edm
    • Propose location to the west of meteorological station tower/shelter, needs investigation.
    • Discussion: A good summary of ALMA phase calibration is given in 'Calibration of ALMA' (see p13-14). There are a number of sources of the overall budget for delay in that document, which includes the atmospheric portion. For any measurement made with ALMA itself of course, there will be a combination of all the sources of delay present in the data. Atmospheric delay was measured during the site characterization phase of ALMA construction using an independent instrument, a 'Site Testing Interferometer' (STI) operating at 11.2 GHz. In this instrument, two antennae at the ends of a 300m East-West baseline observed a geostationary Intelsat satellite signal. The satellite position was 35 degrees above the horizon. Some results from this instrument and similar instruments operated at other locations on Chajnantor are given in ALMA Memo 365 and references cited therein; complete data through August 2009 may be found here. ALMA Memo 361 provides a comparison with observations of an atmospheric tipper operated at 183 GHz, demonstrating excellent correlation. The joint distribution of phase and opacity is presented and discussed in ALMA Memo 521, which shows that there are times when atmospheric phase fluctuations can be large but opacity low. It is planned to use a tipping radiometer at 183 GHz to provide opacity estimates.
    • An operations version of the STI, which will be called an 'Atmospheric Phase Monitor' (APM) to distinguish it, could provide that information. The STI itself operated until September 2009, when a cable was severed by a bulldozer excavating between its antennas. Here is the current state of the cable:
    • Another such instrument currently provides phase information for the EVLA. The STI could be refurbished for a modest sum (few thousand dollars, plus some engineering time) to provide a monitor of atmospheric phase.
  • (BojanNikolic:) A large amount of information on stability of the atmosphere can be extracted from the WVR data. In particular it should be noted that it is total fluctuation measurement, in contrast to the difference measurement that is provided by an interferometer (either ALMA itself or the STI). See examples of some data reductions

Science Corner

  1. Panel Reports from 'New Worlds, New Horizons in Astronomy and Astrophysics' (prepublication version)


  1. Next meeting is on Oct 20th (14:30 UT). Nov 17th 2010 for the following month.

Events of Interest

(see also Al's ALMA Monthly/Biweekly Calendar)

Sep 15
Oct 7-8
CSV Status Update
Oct 11-12
SciOps Readiness Review
Oct 13-14
ASAC f2f
Oct 20
Oct 25-28
Annual ALMA External Review
Nov 10
Observatory Readiness Review
Nov 17
Nov 16-18
ALMA Board Meeting
Nov 22
Date for decision on ES

Upcoming Meetings

The 5th Zermatt ISM Symposium: Conditions and impact of star formation: New results with Herschel and beyond 19-24 September 2010, Zermatt, Switzerland

Stormy Cosmos: The Evolving Interstellar Medium: Recent Progress from Space IR/Submm 1 - 4 November 2010 Pasadena, CA Hosted by the NASA Herschel Science Center, Spitzer Science Center

The Impact of Herschel Surveys on ALMA Early Science Garching, November 17-19, 2010

Observing with ALMA--Early Science IRAM, 29 Nov - 1 Dec 2010

217th AAS Seattle, WA Observing with ALMA - Special Session- January 12, 2011 2:00 PM

15-17 Jan 2011 Workshop ALMA: Extending the Limits of Astrophysical Spectroscopy in Victoria

The Molecular Universe May 30 - June 3, 2011 Toledo, Spain

Recent Meetings (presentations online)

-- AlWootten - 2010-09-13

Topic attachments
I Attachment Action Size Date Who Comment
ALMA_Report_2010_07.pdfpdf ALMA_Report_2010_07.pdf manage 581 K 2010-09-14 - 21:24 RichardHills  
Cable.JPGJPG Cable.JPG manage 241 K 2010-09-14 - 21:55 RichardHills  
IMG00074-20100903-1203.jpgjpg IMG00074-20100903-1203.jpg manage 98 K 2010-09-15 - 02:27 BojanNikolic O2 sounder at the AOS with antennas in the distance
Requirements_for_an_Artificial_Source_on_the_ALMA_Site.pdfpdf Requirements_for_an_Artificial_Source_on_the_ALMA_Site.pdf manage 286 K 2010-09-14 - 21:37 RichardHills  
Science_Milestones_31Aug2010.pdfpdf Science_Milestones_31Aug2010.pdf manage 25 K 2010-09-15 - 10:10 AlWootten Science Miletsones 31 Aug update.
Vertex_Antenna_Surface_Problem.pdfpdf Vertex_Antenna_Surface_Problem.pdf manage 623 K 2010-09-14 - 21:43 RichardHills  
Topic revision: r8 - 2010-09-28, RichardHills
This site is powered by FoswikiCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding NRAO Public Wiki? Send feedback