Minutes for meeting Mon, 20 December 1999 at 4pm EST.
Date: 20 December 1999
Time: 4:00 pm EST (2:00 pm Socorro, 2:00 pm Tucson)
Phone: (804)296-7082 (CV SoundStation Premier Conference phone).
Past minutes, etc on MMA Imaging and Calibration Division Page
Minutes
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From the Division Heads meeting.
FY2000 Budget due. Any input?
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The next meeting will be in Socorro; a two day working meeting on Jan 13-14.
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Date: 22 December 1999
Time: 12:00 pm EST (1700 UT, 1800 CET, 0900 PST)
Phone: I will start the call by dialing 1-888-566-6189.
The passcode for this call is: 1234 - each caller will need to know
this passcode and my name (conference leader--I am Al Wootten).
The U.S. callers will dial: 1-888-566-6189
International callers will dial 415-228-4857
Conway and Mundy will be contacted separately after the call begins.
Motivation:
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The ALMA architecture and engineering site plan for Chajnantor is due
on 1Q 2002, and the site construction is set to begin on 1Q 2003.
Thus we should produce and offer a concrete configuration plan by
early 2001, including real antenna pad positions, reconfiguration
plans, etc...
Gordon says:
1. I need to have an idea of the configuration to prepare the next estimate
of the ALMA cost of developing the Chilean sites. This date is March 2000.
2. To hire an architect and let contracts for the development of the site
itself, the ALMA construction staff will need to know the configuration
somewhere from December 2000 up to, say, 2002. The uncertainty derives from
the fuzziness of the development tasks.
Also, the Environmental Impact Statement will not need specific locations for
antennas, just general ones. As sites are specifically identified, they
will be forwarded to the EIS study group for their information.
Goals:
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Bring together (and perform) all relevant works to address the key
questions related to array configurations and make decisions and
recommendations on each of the questions. We want to at least narrow
down the focus of the configuration work and produce hard decisions
where necessary.
Bryan Butler, Al Wootten, Mark Holdaway, Simon Radford and Min Yun
have defined some of the issues and suggested approaches in a rough
text.
Proposed approach:
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We propose to form a "Configuration Working Group" (CWG), similar to
the science software working group (and similar to the old MMA
Configuration Working Group), composed of members from NRAO/MDC and the
European parties and possibly outside observers/contributors. The
exact composition of the CWG is yet to be determined, and will be
discussed in an early phone meeting (see below).
The CWG will be closely associated with the Imaging and Calibration
(NRAO) and Science and Systems (Europe) groups, and the ASAC, and will
make recommendations to the AEC on all issues related to array
configurations.
The CWG will meet for regular phone meetings and have occassional
face to face meetings including the configurations PDR and CDR
(timing and frequency of all to be determined).
Phone Meetings
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The frequency of phone meetings is to be determined, but to start
things off (and to discuss the makeup of the CWG), we will have a
kick-off phone meeting on 22Dec1999. This phone meeting will begin at
1700 UT (1200 EST, 1000 MST, 0900 PST). We
intend to have a second phone meeting on 05Jan2000, same time and
number (though this may change given the results of the first phone
meeting).
Invitees to initial phone meeting:
M. Yun, B. Butler, S. Radford, A. Wootten, L. Kogan, M. Holdaway,
D. Shepher, E. Fomalont (NRAO)
D. Woody, T. Helfer, L. Mundy (MDC)
S. Guilloteau, F. Viallefond, J. Conway, A. Webster (Europe)
Face to Face Meetings
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We would like to have the first face to face meeting in
March of 2000. Of course this depends on the progress via the phone
meetings. In any case, we propose to have the first of the face to
face meetings in Tucson. Two days seems sufficient for this meeting.
If we held it in Tucson, a good possible date is Monday-Tuesday, March
20-21.
Participants in the face to face meetings will be the members of the
CWG, and possibly other members of the Imaging and Calibration and
Science and Systems groups, and other NRAO, European, Japanese and outside
observers/participants.
An Initial List of Topics to be Addressed and Discussed
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1) Logistics
Who is in the group?
How often do we meet (both phone and face to face)?
Monthly phone meetings? more often?
Report to ASAC meeting 10 March 2000?
Face-to-face review 20-21 March 2000?
PDR?
2) Basic configuration parameters: number, sizes (150 m to >10 km)
is 64 antennas the right number to use?
is 150m, 450m, 1.35km, 4km, 12km the right number/scaling for
the configurations?
should very complex optimization be attempted?
3) Styles (rings, donuts, sprials, etc...)
Choosing antenna locations
political issues
topography issues
Imaging quality
Status of current studies
packages include miriad, Gildas, AIPS, AIPS++, Gypsy
what are pros and cons of each?
Future studies
what is the metric we should use to guage the "quality"
of a given hypothetical configuration?
consistency of simulations
what should the simulations have in common?
should there be a "standard image library" and if
so what goes in it?
Philosophy
tapering
configuration change frequency and style
pad re-use
operations impacts
4) Concrete plan for further progress.
Task assignment
Copies of Conway's proto-memo and some other stuff, test images
etc can be found via his home page at
Chalmers .
See also Min's page at
the AOC.
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Second Joint ALMA Science Advisory Committee Meeting 13 Dec 1999.
SAC members have been appointed.
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ALMA Science Advisory Committee Meeting
Date: 20 December 1999
Preliminary minutes are at: ASAC Minutes.
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Action Items 20 December 99
DECISION: Configurations--where are we? Feb meeting plans...
DECISION: 183 GHz or 22 GHz phase correction?
DECISION: Is a nutating secondary necessary?
DECISION: What is the effect of 1/f noise in the HEMT amplifiers of SIS receivers upon our ability to combine total power and interferometric images into a faithful representation of the sky?
MEETINGS: SAC meeting 10 Jan 1999 for members only.
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Travel
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