2007-07-12 ALMA Calibration Group Telecon Agenda and Minutes
ALMA Calibration Group Telecon
- Date: July 12, 2007 (Thursday)
- Time: 14:00 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
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Table of Contents:
Action Items from Last Telecon
Assigned To | Due Date | Description | State | Notify | |
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Agenda and Minutes
NOTE: Discussion from the telecon is shown in italic.
Attendees
- JeffMangum
- Richard Hills
- BojanNikolic
- Lars-Ake Nyman
- Alison Peck
- JohnRicher
- LeonardoTesti
- AlWootten
Calibration Examples Status
Still waiting on final versions of bandpass (
RobertLucas), delay (
RobertLucas), polarization (
EdFomalont), optics (
BaltasarVilaVilaro), and ACA calibration issues (
EdFomalont) calibration examples. See
CalExamples wiki for further information.
Calibration Sequence Development
Will begin process of turning
CalExamples into calibration "sequences" during 2007Q3. Need to first meet with Computing IPT to figure out which Computing IPT personnel will be available to participate in sequence development.
Noted by Richard Hills: Computing and Science IPTs need to get to work on Sequence development soon. AlWootten notes that extended lifetime of the ATF affords an opportunity to develop and test Sequences before they are needed in Chile.
Amplitude Calibration Subsystem Development Reports
- Berkeley Absolute Flux Calibration System (Jack Welch)
- Semi-Transparent Vane (STV) Calibration System
- Received final report on 2007/07/11. This item is now officially closed.
- Multi/Dual-Load (M/DL) Calibration System (Ferdinand Patt)
- Ferdinand Patt noted before the meeting that the robotic arm system for the calibration device passed its FDR (with a few minor issues to resolve). Company building robotic arm is NTE (Spain). Also, Ferdinand expects the load test report from IAP (Institute doing the test for ALMA) to be available by the end of this week.
Weather (Ancilliary) Measurement Devices
In December 2006
JeffMangum submitted weather station instrumentation (RH, P, T, and wind) RFQ documentation to NRAO procurement system. After having reviewed information received from bidders and consulted with Calibration Group (see
CalAncillary for discussion), on 2007/03/21
JeffMangum submitted purchase information to
RobertLaing for procurement.
Leonardo Testi continues to push purchase through ESO purchasing system. Will likely obtain a loaner set of weather devices from Vaisala to allow us to test the integrated system either at ESO or NRAO.
Oxygen Sounder
JohnRicher has developed a contact with one of the companies that
produces O2 sounders. With
BojanNikolic, they are investigating
issues related to operating such a device at 5000 m, among other
things.
One of the companies that produces O2 sounders has recently been doing
a study for a site at 3300m asl and so they have a good idea of
expected performance at high elevations. They have told us that they
expect accuracy of about 0.5K in the first kilometre of the atmosphere
and about 1K accuracy higher up. This is a bit better than previously
expected and is likely to be good enough for atmospheric phase
correction purposes.
There is, however, one obstacle. The algorithm to invert the
radiometer measurements to a vertical temperature profile is based on
a neural network and requires a large training set to function
properly. We have been told that something like 10 years of daily
radiosonde launches are required. We currently looking at what data
are available in the vicinity of the ALMA site. --
BojanNikolic
Question regarding purchasing process. Since budget in on NRAO side of the ALMA budget, what are requirements for purchasing? Likely requires an RFQ with bid evaluation. JohnRicher and BojanNikolic will continue to investigate potential vendors and devices.
Solar Observations and Calibration
MarkHoldaway has written a draft document on
Calibration of Solar Observations. We discussed this document at our last telecon. Few revisions are needed.
MarkHoldaway will update and submit final version within the coming few weeks.
Date of Next Phone Meeting
The next ALMA Calibration Group telecon will be
2007, August 16th 14:00 UT (shifted by +1 week).
--
JeffMangum - 12 Jul 2007