[fitsbits] EXPOSURE or OBSTIME?

[Tom Kuiper]

> Date: Mon, 5 Jun 2000 14:03:45 -0700
> From: Steve Allen <sla at ucolick.org>
> To: FITSbits <fitsbits at nrao.edu>
> Subject: Re: [fitsbits] EXPOSURE or OBSTIME?
...
> On Mon 2000-06-05T11:34:09 -0700, Tom Kuiper hath writ:
> > I'm leaning towards a solution similar to that used at Lick, where they have
> > both the keywords EXPOSURE and TTIME, which mean the same thing, the latter
> > being there for backward compatibility.
> 
> Although I'm the one that pointed to this way of doing things, I'd
> like to assert that I don't think it is a good idea.  Duplicating the
> same value into two different keywords was an engineering tradeoff
> adopted for reasons more political than technical.

Dear Steve,

Why don't you think it is a good idea?  I don't see any problem with it, though
it isn't esthetic.  Storage conservations isn't an issue anymore.  The only
problem I could see is if the program generating the file messes up and
gives different values to the supposedly synonymous keywords.
> 
> It should have been avoided, and would have if a data reduction
> package in use had a means for translating keywords in the fashion
> akin to that provided by IRAF.

That strikes as cumbersome.  It means that when my program writes a FITS
file, I have to keep in mind whether the recipient has this capability and,
if not, what variant of FITS it understands.  I think we're stuck here with
backward compatibility to a time when there was keyword chaos.

Cheers

Tom
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