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Contact Information

  • 2008-4-16 14:30 UT Please check your local time; it may have changed!
  • Note: C. Wilson points out line noise may be muted by pressing *6 which works thru the call center.
  • Duration: 1 hr
  • USA Toll Free Number: 877-874-1919
  • Toll Number: +1-203-320-9891
  • Passcode: 185064
  • Leader: Al Wootten
  • Attendees: Remy, Rob, Jeff, Antonio, Crystal, Al, Meredith, Todd, Hills, Morita, Vila-Vilaro, Testi, Hibbard, Nikolic, Richer, Emerson, Lucas


  1. Old Business The enhanced Agenda from last meeting is available. Science IPT notes from last month's telecon are attached to the bottom of the agenda.

Transporters carry dummy antenna load to new heights The transporters carrying a dummy antenna load on the road to the AOS high site.

See other images and animations. See other images and transporters.

  1. New Business--Project news/updates (Hills, Peck)

  1. Directories

Science IPT Group Activity Reports

Please include your Group Activity Report here (How to Enter Your Report), or email it to AlWootten

Project Scientists

  1. Science IPT - Follow up from last meeting
    • Change Control Board items, other technical concerns (Hills)
      • Discussion on cartridge availability in front ends. (Hills)
      • Polarization. See discussion items circulated by Hills.
      • LO Phase lock bandwidth. CRE 179 proposes reducing this which should reduce phase noise at the highest frequencies but lose a little efficiency from the lag when phase switching.
      • Line Stretcher Compensation Is it really necessary to use a closed-loop servo to compensate for the line-length changes or would it be sufficient to simply measure the changes and correct them all in software - either by adjusting the LO phase or in the data reduction? Follow link to attachment please for discussion.
      • Acceleration of the 7m ACA antennas. CRE 184 proposes reducing the maximum accelerations and demonstrates that the loss of observing efficiency will be small. See table at Jan 2007 discussion.
      • Here Draft Front End Pointing CRE is a first version of a change request aimed at ensuring that the any pointing errors arising due to deflections in the front end are small. Differential movements between the receivers would be particularly damaging to offset pointing.
      • QuarterwavePlates are suggested for B7. A proposed specification is among FE IPT documents. We proposed these to begin a dialog with FE in July 2006. At that time there was a f2f meeting with FE and Sci here in Cville. A reply was posted to edm 14 months later calling for review and approval of these specifications; I am unaware that this was discussed in a science or cal group meeting. Let us proceed: is the proposed bandwidth and center agreed? How accurately does it need to be a quarter wave? A memo on the SMA device is attached at the bottom of the agenda for last month.
    • ATF: (Peck)
      • Summary. ATF lifetime to be extended. First spectrum has been obtained by the system and processed through CASA. Remy, George and Al are working on it and will send around a report soon.
      • Goals: (1) Get software working (2) Training personnel and developing procedures
      • Spectral-line pointing needs to be available in Q1 2008 for single dish testing in Chile.
      • The current schedule is below. Please let Alison and Debra know if anyone has any issues with this. During the current period foci of interest include further understanding of the behavior of the Line Length Corrector, to measure the baseline correctly and to begin interferometric pointing.
Week Event
Apr 7
Indebetouw, Wootten, Peck
Apr 14
Peck, Hills, Johnstone
Apr 21
Johnstone, Reid
Apr 28
Reid, Hales
May 5
Hales, Diego
May 12
Diego, Hales
May 19

  • OSF
Week Event
Mar ?
Emerson VxRSI antenna contractor handover testing begins 4 Feb

  1. Next meeting is on May 21st (14:30 UT). June 18th for the following month.
  2. Astronomer Outreach: New ESO ALMA Webpages.][NRAO Newsletter]]. NAOJ News. NRAO ALMA Calendar

Emerson/Laing/Vila-Vilaro -- Instrument Scientists

  • Phase jump across scan boundaries. We discovered at the ATF that the phase is reset at scan boundaries, as there is no requirement to maintain it. Q: Should this be a requirement? (Emerson)
  • Sci IPT at the ATF Checklists, Progress Reports.
  • CIPT Wiki Daily ATF reports.

Richard Hills, Alison Peck, Robert Laing -- Commissioning and Science Verification

  • Commissioning and Science Verification

Holdaway, Reid -- Configuration Group

Steve Myers/Rob Reid (Mark Holdaway)-- Imaging

  • A set of ALMA PSFs with varying amounts of robust weighting has been made and summarized in weighting.html. It will be useful for determining how much Briggs weighting to use when, but the most immediately interesting result is that it should be possible to use any resolution in the ALMA range with only a litte reweighting: . The set is being extended with tapered beams.
  • CASA Simulator Report
    • The Library of standard ALMA images for simulation is available.
    • Fidelities over 104 have been achieved for 4 hour noiseless "observations" of the M31 HII region, using deep cleans with a tightly constrained support region.
    • CASA simulation wiki with examples
    • Bojan Nikolic is using the simulator to make u-v data and maps when investigating the effects of atmospheric phase and, in the future, for trying out phase-correction techniques.
  • Pointing selfcalibration for mosaics

Jeff Mangum -- Calibration

  • Response to ASAC comments
  • Pointing Design document now drafted.
  • Calibration Plan: Current version of the calibration plan and associated documents ("examples", "roadmaps", "matrices", etc.) posted. Comments welcome.
  • Calibration Examples: The "meat" of the Calibration Plan. Review of these documents nearly complete, some need updates.
  • Ancillary Calibration Devices: Documents which describe the weather station and temperature profile technical specifications have been developed. Initial purchase documentation for (P,T,RH,Ws,Wdir) measurement devices has been made by Leonardo.

Robert Lucas -- SSR

  • Latest SSR meeting (2008-04-09).
  • Testing of integrated system at the ATF, using data in ASDM format.
  • Testing of TelCal: phase measurement, delay measurement, phase curve .
  • ACA Correlator integration work continued

Michiel Hogerheijde -- DRSP

  • No progress on including the author responses to the referee comments, the DRSP 2.0 web site continues to be password protected. If you would like access (keeping in mind that the author responses have not been added yet) use: username=review and password=chajnantor! (including the exclamation mark).

L.-A. Nyman -- Site Characterization

Remijan, Markwick-Kemper -- ALMA Working Group on Spectral Line Frequencies

Science Corner:

The Formation and Evolution of Prestellar Cores Authors: Philippe André, Shantanu Basu, Shu-ichiro Inutsuka


ALMA Events of Interest

(see also Al's ALMA Biweekly Calendar)
Day Date Time Event location details
April 16
ALMASci Telecon
May 5
ASAC Telecon
May 15
ALMA Board
May 21
ALMASci Telecon
June 18
ALMASci Telecon

Upcoming Meetings

-- AlWootten - 15 Apr 2008
Topic revision: r9 - 2010-08-02, ToddHunter
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