2005-03-10 ALMA Calibration Group Telecon Agenda and Minutes
ALMA Calibration Group Telecon
  • Date: March 10, 2005 (Thursday)
  • Time: 16:00 UT
  • Duration: 1.0 hr
  • USA Toll Free Number: 1-877-919-7148
  • International: +1-203-566-1039
  • Passcode: 5 1 0 4 6 8
  • Leader: JeffMangum

Table of Contents:

Complete List of Action Items

Action Items from Last Telecon

Assigned To Due Date Description State Notify  

Agenda and Minutes

NOTE: Discussion from the telecon is shown in italic.


  1. Matt Carter
  2. JimGibson
  3. JeffMangum

Calibration Plan

Thanks to those who contributed to the recent significant revision to the Calibration Plan. More work needs to be done on this document before it can be considered "done". Recall that we have organized ourselves into small groups concentrate on specific sections of the plan. I list below these groups, with the "lead volunteer" denoted in bold:

  1. Amplitude and Flux Calibration (Welch, Butler, Carter, Gibson, Holdaway, Mangum, Martin-Pintado, Kawabe, Wilson)
  2. Phase Calibration (Hills, Holdaway, Mundy, Richer, Stirling, Wootten)
  3. Bandpass Calibration (Guilloteau, Bacmann)
  4. Polarization Calibration (Myers, Holdaway, Laing)
  5. Pointing Calibration (Mangum, Lucas, Holdaway)
  6. Antenna Location Calibration (Conway, Wright, Morita)
  7. Antenna and Electronic Delay Calibration (Lucas)
  8. Optics Calibration (Butler, Saito)
  9. Total Power Calibration (Holdaway, Mangum, Mundy, Kawabe)
  10. Primary Beam Calibration (Holdaway, Wilson)
  11. Archiving and Accessing Calibration Quantities (Lucas, Mangum)

With regards the updates to the individual Calibration Plan chapters, with the exception of the changes identified through the Action Items, the Calibration Plan appears to be in pretty good shape.

All group members should read through the current version of the plan and suggest changes.

Calibration Group Use of the Wiki

Calibration Category Issues

The following is a list of "calibration categories" which JeffMangum suggests we should discuss on a regular basis (note the similarity to the Calibration Plan sections). Please suggest additions/deletions to the following list.

  1. Amplitude and Flux Calibration
  2. Phase Calibration
  3. Bandpass Calibration
  4. Polarization Calibration
  5. Pointing Calibration
  6. Antenna Location Calibration
  7. Antenna and Electronic Delay Calibration
  8. Optics Calibration
  9. Total Power Calibration
  10. Primary Beam Calibration
  11. Archiving and Accessing Calibration Quantities

Before this telecon it was suggested that we discuss issues related to the following three calibration categories:

  1. Amplitude and Flux Calibration (Welch)
    • See relevant discussion in Amplitude Calibration Subsystem section next.
  2. Bandpass Calibration (Guilloteau)
    • No discussion on this topic.

Amplitude Calibration Subsystem Development Reports

  • Berkeley Absolute Flux Calibration System (JimGibson/Welch)
    • Continue to work on data analysis of measurements made at BIMA last fall. More systematics found than anticipated. Also still need to measure loss of waveguide at CU.
  • Semi-Transparent Vane (STV) Calibration System (ThomasWilson)
    • No report.
  • Multi-Load (ML) Calibration System (Matt Carter)
    • Good progress made on this development. Measurements of RAL load stability made with a HEMT amplifier look promising. Measure \Delta T = \pm 0.5 K at 100 GHz. Will measure at 300 GHz next week. HEMT amplifier is not really stable enough to do these measurements, so will try a Schottky amplifier in subsequent measurements. Will complete measurements in 2-3 weeks. All-in-all, results so far look promising for heated load stability.
Assigned to Due date Description State Notify  
JeffMangum 2005-09-01 "Recommendation document" describing decision on amplitude calibration device. Requires input regarding ST and ML calibration device performance. (go to action) closed JeffMangum edit

Weather (Ancilliary) Measurement Devices

At the 2004-11-09 telecon AlWootten started a discussion of the state of the "ancilliary" measurement devices (generally, weather measurement devices). AlWootten pointed out that the Project will soon go through a "rebaselining" exercise, which will involve a reorganization of the scope of the Project. Since ancilliary devices are not currently funded, we need to make the case for the necessary ancilliary devices now. Jack Welch suggested that an oxygen sounder would be very useful to have. AlisonStirling has posted her review of oxygen sounders to the CalAncillary wiki.

Date of Next Phone Meeting

The next ALMA Calibration Group telecon will be 2005, April 14th 16:00 UT. This is our "normal" meeting time (16:00 UT on the second thursday of each month).

-- JeffMangum - 14 Mar 2005
Topic revision: r18 - 2006-12-02, TWikiGuest
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