[fitsmime] FITS MIME Considerations

[William Pence]

William Thompson wrote:
>
> While I'm in general agreement with Lucio's excellently written message, I feel
> I must take exception to the above.  The extension of the file should always
> tell you what the format of the file is, i.e. whether it is FITS, CDF, netCDF,
> HDF, etc., or even one of the image formats, GIF, JPEG, etc.  I feel very
> strongly about that.

Within high-energy astrophysics most missions don't label their data files
with a unique extension like '.fits'.   Since the data are always assumed to
be in FITS format, it would be redundant to add an extra '.fits' to every
filename, not to mention an added burden to users who sometimes have to type
in the long filenames on the command line.   The extension characters are
usually reserved to identify the scientific content of the file, as in these
examples

ad60033000g200270h.evt  (event file)
xh30216010404_b0c.lc    (light curve)

One current mission that does add a FITS suffix to every filename is
XMM-Newton, which has filenames like 
0277_0136550201_M1X00000PTH.FIT
P0136550201R1S004BGSPEC1001.FTZ

where .FTZ means it is a gzip compressed FITS file.

Given this widespread practice of not using a standard suffix for every FITS
format file, I don't think we can expect to introduce such a standard now. 
Personally, I think the flexibility and freedom in specifying FITS filenames
is much more important to users than the advantages that would be gained by
always using the same .fits suffix (such as making it easier to assign mime
types to the files).  

Bill Pence
-- 
____________________________________________________________________
Dr. William Pence                          William.D.Pence at nasa.gov
NASA/GSFC Code 662         HEASARC         +1-301-286-4599 (voice)     
Greenbelt MD 20771                         +1-301-286-1684 (fax)