[alma-config] Teleconference 31 Jan 2001 at 1600UT?

[John Conway]

Hi,

 Unfortunately I will be in a meeting at 1600UT tomorrow (our 
annual evaluation of PhD students), it should be finished
by 6.00pm local time here or 1700UT. Could the telecon 
be delayed until then? Having it the next day is also 
a possibility.

Sorry I didn't read the email below yesterday but 
I was in town  and the telnet connection to the 
observatory was down.

   Cheers
       John
    


On Mon, 29 Jan 2001, Al Wootten wrote:

> Copy with more extended text and hyperlinks at
> http://www.cv.nrao.edu/~awootten/html/almaconfig4jan01min.html
> 
> Next teleconference 31 Jan 2001 at 1600UT?  Comments?
> 
> Minutes of Meeting 4 Jan 2001
> 
> Attendees: Wootten, Guilloteau, Pety, Gueth, Webster, Heddle, Morita,
> Conway, Yun, Butler, Kogan, Wright
> 
> Next Meeting
> 
> Another phone meeting was suggested, to discuss the metrics.
> Date: 31 Jan 2001 at 1600UT?
> 
> 
> PDR
> 
> Since the teleconference, both Lee Mundy (lgm at astro.umd.edu) of the
> University of Maryland BIMA Group, and Eric Anterrieu
> (Eric.Anterrieu at cerfacs.fr) of (Signal & Image Processing Team), CERFACS, at
> Toulouse have agreed to serve as external referees.  Mel Wright has also
> been invited.
> 
> Simulations
> 
> There was considerable discussion on the error images and statistics which
> Steven has placed at his WWW site. Steven distributed his report.
> 
> Metrics
> 
> John suggested that we arrive at the metric iteratively and collected the
> emails to alma-config on the subject. Summary of discussions at the
> teleconference:
> 
> Principle: The metric should not depend on the character of the array.
> 
> It was generally agreed that negative values should be suppressed in some
> way. There was general agreement that model image pixels could be magic
> value blanked at some percentage of the peak, then one could divide the
> model and produced images to obtain fractional error and fidelity indeces.
> The 'median fidelity' could be extracted at percentages of the peak--1 per
> cent, ten per cent, and so on. Then this and fractional error can be plotted
> as a function of which percentage was used in the model image The rms for an
> image could be defined as the mean from the whole difference image over a
> region where there is signal, e.g. the unblanked region. This is covered
> in Steven's items 1 and 4.
> 
> Discussion also centered on how to treat the fact that differing content of
> short spacings dominates the images. This could be addressed by adding in
> data from a smaller array. It was decided that it would be excellent if
> Heddle were to simulate some multiconfiguration images, including B and D
> array data, for e.g. M51 and Cygnus models images. This is item 5 on
> Heddle's list.
> 
> Since then, there has been some discussion on the dots image.  There are
> ALMA simulations with FITS images at:
> http://www.cv.nrao.edu/~awootten/mmaimcal/newzlines.html
> or John has distributed his DOTS image.  Steven is working on the latter.
> 
> Bryan has made an attempt to summarize metric discussion which I understand
> he will distribute shortly.
> 
>