Date: JAN-31-2001 (Wednesday) 31 January 2001.
Time: 12:00 EST (10:00 MST, 1700UT)
USA Toll Free Number: 1-888-323-9872
International Number: 1-630-395-0180
Passcode: ALMA
Conference leader: Al Wootten
Past minutes, etc on ALMA Configuration Group Page
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Attendees to the meeting are asked to send their talk proposals, time estimates, and attendance details to Stephane and to Al so that the agenda may be assembled and documents supporting it corralled.
Conway and Heddle will work on producing two metrics for the images for the meeting. Heddle reports (2/7/01) having replaced the existing situation on his pages of two side by side fidelity histograms with 1) a histogram showing both the previous plots on one graph, next to 2) a histogram showing the 'cumulative' curves. The cumulative curves show fidelity on the x axis, with the y value showing log10(number of pixels with a fidelity greater than x).
In another plot, the rms in the fractional error maps will be compared, probably by blanking several times over intensity steps, calculating the rms each time.
Details for the Configuration PDR
1) Date and Place
Date: February 26 and 27
Location: IRAM, Grenoble
2) Attendant List (Plausible attendees only)
3) Documents
To be ready 2 weeks in advance for distribution, specially to the outside members. We already have a lot, but are weak on operation issues. Links to most material are available at the ALMA Configuration Development WWW pages at The ALMA WWW Site. A good summary is given in the Project Book Chapter on Configurations.
- Nested Ring concept (Yun / Butler) Summary and ALMA Memo No. 320 Strawperson Donut/Doubling-Ring Configurations by M.S. Yun & L. Kogan.
- Spiral concept (Conway) See Conway's WWW site and specifically his Protomemo A Preliminary ALMA Zoom Array Design for the Chanjnantor Site by J. Conway.
- Simulations (Heddle) The guidelines from the meeting in March 2000 led to the creation of the Image Library . These images were then run through a set of AIPS simulations by Heddle, with these results.
- Multi-configuration aspects (Viallefond) Document??
- Compact array issues (Morita / Guilloteau) The summary may be seen at my site.
- Site issues (Radford / Butler)
- Operation concepts (Wootten / Guilloteau)
- Cost issues (Hofstadt / ? )
Goal of the meeting: select a baseline design to continue with detailed implementation work ...
John asked that UVCON which currently employs 100 stations, couldn't be increased to 2017.
Bryan's useful memo, wih comment by Woody and Wright was discussed. Stephane pointed out that residual errors in the maps seem proportional to the original sidelobe levels; though not proven this appears to be true from examination of the images. There was some agreement that among the uv metrics a beam metric was a useful tool for evaluation.
Attendees to the meeting are asked to send their talk proposals, time estimates, and attendance details to Stephane and to Al so that the agenda may be assembled and documents supporting it corralled.
Conway and Heddle will work on producing two metrics for the images for the meeting. Heddle reports (2/7/01) having replaced the existing situation on his pages of two side by side fidelity histograms with 1) a histogram showing both the previous plots on one graph, next to 2) a histogram showing the 'cumulative' curves. The cumulative curves show fidelity on the x axis, with the y value showing log10(number of pixels with a fidelity greater than x). In another plot, the rms in the error maps will be compared, probably by blanking several times over intensity steps, calculating the rms each time.