[fitsbits] FIT Keyword data dictionaries

[Peter Bunclark]

Doug Mink wrote:

> Mark Calabretta wrote:
> >
> > On Mon 2000/11/06 08:48:08 -0000, Patrick Wallace wrote
>
> ....#
> I actually had occasion to generate images of the sky at a specific historical
> time, and it seemed appropriate to generate them in alt-az coordinates.  Here
> is the relevant portion of the header I wrote for a south-centered image of
> the sky as seen on a specific night in Rome:
>
> DATE-OBS= '1611-04-15'
> UT      = '00:00:00'
> CTYPE1  = 'AZ---LIN'

The FITS standard tell us that DATE-OBS ``...value field shall contain a
character
 string giving the day on which the observations represented by the array were
 made...''  so is it, in fact, an appropriate keyword to represent the epoch of
an artificially-generated map given that the observations used were presumably
made much later?

Pete.