[daip] Re: aips max # stations

[Leonia Kogan]

Hi Chris,

As I remember UVCON works untill number of antennas <2000.
If the number GT.255 then selection (ANTENNA,BASELINE) will not work 
with the output of UVCON because the decoding antennas from baseline.
But such a task (for example) as IMAGR should work because it works 
directely with UVW(?)

So you can try

Leonia
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>From daip-admin at donar.cv.nrao.edu Fri Mar 26 13:25 MST 2004
From: Eric Greisen <egreisen at nrao.edu>
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Subject: [daip] Re: aips max # stations
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Date: Fri, 26 Mar 2004 13:24:22 -0700
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Chris Phillips writes:
 > Hi Eric,
 > 
 > I am interested in using aips (UVCON) for some SKA simulations. If I
 > understand correctly aips has a maximum # stations of 255 due to the way
 > station numbers and encoded in baselines.
 > 
 > Is this correct? I need >300 stations. I also assume this is a pretty
 > fundamental limit (no recompiling with a changed .inc file to increase the
 > number).
 > 

This is a very deep problem - I think UVCON ignores it at some level
but then baseline selection etc does not work.  I think SKA
simulations have been done but we have a problem with th3 whole
concept of including a baseline number as n*I + J - one can easily
exceed the accuracy of counting with floating point.  Sault introduced
a concept of using a dual system with a larger n - if the "baseline
number" > his larger n then it is his system else it is the old system
- but I hate to tell you how many 1000's of line that would affect.
And his schem still does not cover the needs of some SKA models.

Eric

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