[daip] FITS Antenna tables

[Leonia Kogan]

Dear David,

There is no (unfortunately) the only coordinate system used for all arrays 
in the AN table.

I give you the two examples.

VLBA:  uses the left handed coordinate system with X directed to the greenwich 
       meridian.

VLA:   uses the right handed coordinate system with X directed to the meridian
       of the array center. 
       The array center coordinates are given the right handed coordinate 
       system with X directed to the greenwich  meridian. 
       The array center coordinates appear at the header of the antenna 
       table as Array BX=-1601162.0   BY=  -5042003.0   BZ=   3554915.0
      

AIPS reads the array name (Array=VLA, VLBA, ATCA...) from the antenna table and 
selects the relevant coordinate system.

Regards

Leonia



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>From owner-daip at kochab.cv.nrao.edu Thu Nov  9 08:38 MST 2000
To: aipsmail at cv3.cv.nrao.edu
Subject: [daip] FITS Antenna tables
Cc: djt at mrao.cam.ac.uk
From: David Titterington <djt at mrao.cam.ac.uk>
Date: Thu, 09 Nov 2000 14:10:35 +0000
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Dear AIPS,

We are writing UV data from one of our instruments in FITS format for
import to AIPS, and need to add the antenna tables as an extension to
the FITS file, but I haven't so far been able to find a reference in
the documentation which will tell me the coordinate system expected
by AIPS for the antenna positions.

Could you point me in the right direction, please?

Many thanks,

David Titterington,
Mullard Radio Astronomy Observatory,
University of Cambridge,
Cambridge, UK.


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