[fitswcs] [Fwd: PV index perhaps wrong in version 3.0]

[William Pence]

The question below was sent to the FITS support office.  Is Table 8.1 in 
the FITS Standand incorrect?  Should it state that LONPOLEa and LATPOLEa 
are associated with PVi_3a and PVi_4a instead of PVi_1a and PVi_2a?

Bill

-------- Original Message --------
Subject: PV index perhaps wrong in version 3.0
Date: Mon, 08 Sep 2008 14:35:34 +0200
From: Vogelaar M.G.R. <vogelaar at astro.rug.nl>
To: fits at asd.gsfc.nasa.gov

L.S.,

Table 8.1 section 8, page 74 lists for the native longitude and latitude
  of the celestial pole the keywords LONPOLEa= and LATPOLEa= which,
according to the table is equivalent to PVi_1a and PVi_2a.
However, in the same table these keywords were previously attached to
the fiducial point. Also Calabretta and Greisen use PVi_3a and PVi_4a in
their article 'Representations of celestial coordinates in FITS'.
Please can you inform me about what is right (i.e. standard FITS) in
this case?

Best regards,
Martin Vogelaar
Kapteyn Astronomical Institute
Groningen,
The Netherlands
( vogelaar at astro.rug.nl )

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