[fitsbits] FITS 'keyword dictionaries'

[Steve Allen]

On Thu 2014-04-03T15:08:45 -0400, Joe Hourcle hath writ:
> here's what I submitted:

> Standardizing Documentation of FITS Headers

> External documentation may be needed to determine what the values
> are of coded values or unfamiliar acronyms.

This is lamentable, but it will remain a fact of life because ...

> Different communities have interpreted keywords slightly
> differently.  This has resulted in ambiguous fields such as DATE-OBS,
> which could be either the start or mid-point of an observation.[2]

the design of some instruments never specified that there be
mechanisms for acquiring the data necessary for such FITS keywords.
As a particular example, the times at which the shutters moved
http://www.ucolick.org/~sla/fits/kecktime.html

> We present what we believe is needed for a machine-actionable
> external file describing a given collection of FITS files.  We seek
> comments from data producers, archives, and those writing software to
> help develop a single, useful, implementable standard.

This effort has to reach all the way back to encourage the funding of
the infrastructure that will be necessary for an instrument and
telescope to supply reliable values for these standardized FITS keywords.

--
Steve Allen                 <sla at ucolick.org>                WGS-84 (GPS)
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