FEIC Beam scanning meeting -- 2008 August 20

Attendees

  • CV: Todd, Goeff, Josh, Antonio, Fred, Sri
  • Tucson: Darrel

Minutes (from Darrel)

An incomplete list from today's meeting:

  1. There's still a discrepancy between our calculations (using Richard's revised spreadsheet) and Andrey's results, for the same Band 9 data. Derived efficiencies differ by ~2%, and beam pointing by 0.3 degrees.
  2. There are inconsistent results using different probes. It seems that the NSI corrections for the probe patterns may not be working properly, for whatever reason.
  3. The new IF processor has been installed and tested, but no scans have yet been made using it. The new processor should be more stable and has a flatter passband.
  4. The open-ended waveguide feed for Band 9 is now available.
  5. Similar feeds for the other bands will not be available for about 2 months.
  6. Antonio reported that the 3 mm test uncooled test receiver would be available within 3 weeks.

We agreed to hold another meeting on Thursday August 28th, probably at 14:30 CV time (21:30 UT). Darrel will confirm later. In time for that meeting, the following actions will have been completed:
  • Geoff will make measurements with the Band 9 open waveguide feed and report on the results.
  • Josh will reanalyse the bands 6 and 7 PAI data, using the latest spreadsheet originating from Richard.
  • We need to sort out the discrepancy with Andrey's analysis. Antonio will talk to Andrey, and Josh and/or Todd will set up a simple wiki page so that Andrey's intermediate analyses and our own can be compared directly. We will then arrange a teleconference involving Andrey, Richard and other members or this group to home in on what Andrey is doing differently from ourselves. This should be done as soon as practical. Antonio will find out Andrey's availability to arrange a suitable time for this teleconference.
  • The discrepancy between NSI analysis of different probe polar diagrams: Todd and Fred will take suitable existing raw data sets for two different probes, and process them themselves - using our own probe pattern correction, and FFT. This will be compared to the NSI analysis. Is the problem with the NSI representation of the polar diagrams, with the NSI analysis, or what?

All the above, and more, will be discussed by this group on Thursday 28th.

-- ToddHunter - 20 Aug 2008

This topic: ALMA > WebHome > FrontEndIntegrationCenter > FEICBeamScanningResults > FEICBeamScanningMeeting2008aug20
Topic revision: 2008-08-20, ToddHunter
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