[mmaimcal] 2nd draft writeup on imaging simulations

[Mark Holdaway]

I've got a second draft -- it is still pretty "drafty",
but has some corrections, larger plots that are easier to read,
one more plot that "explains" (sort of!) the visibility errors in terms
of (u,v) coverage amd source structure.  I just replaced the sim4056.ps
file in the FTP area (instructions below).

After the ASAC Meeting, I will make revisions and clean it up and
put it out as an ALMA Memo.

One thing not addressed in the memo is how multiconfiguration 
imaging could help improve the image fidelity.  My answer:
quite a bit, but to get the most out of that, we would
have to design the arrays with multi-configuration use in mind.
In order to get imaging as good as 56 antennas with only 40, it would
require 2-3 different configurations' data added together.  Convenience
and time are the main losses, but we also must consider the effects
of observing under a different atmosphere, on a different day, when the
calibrators are different, as these things might end up limiting our 
images more than Fourier plane coverage issues.

   -Mark


> 
> I've done a draft writeup of imaging simulations
> for N=40, 43, 46, 50, 56
> 
> You can get the draft report via ftp:
> 
> 
> ftp ftp.tuc.nrao.edu
> anonymous
> YOUR e-mail
> cd mholdawa
> bin
> get   sim4056.ps
> 
> 
> Enjoy
> 
> 
>    -Mark
> 
> 
>