WD for the Obscoredata model and its implementation on TAP

[Arnold Rots]

I have four comments:

Like Tom McGlynn, I find the prescribed unit for the spectral axis
(wavelength) very awkward. Only 1/3 of the community thinks in this
inverse unit. I would strongly suggest allowing wavelength, frequency,
or energy; if we really need to stick with only one, I would suggest
frequency as the most physically meaningful one.

TimeScale is missing from the list.

Reference positions are missing, too. They really need to be there.
One might require them to be the same for space and time, but the
spectral reference needs to be separate.

I commented earlier on the Redshift axis. Its specification requires a
Redshift-Doppler toggle, Doppler definition (optical/radio/relativistic),
a reference position, and possibly the Doppler units (though km/s is
pretty much globally accepted).

I won't harp on my long-standing objections ;-)

Cheers,

  - Arnold


Mireille Louys wrote:
[ Charset ISO-8859-1 unsupported, converting... ]
> 
> Dear dal & dm members,
> 
> I uploaded the last version of the WD here :
> 
> http://www.ivoa.net/cgi-bin/twiki/bin/view/IVOA/ObsDMCoreComponents
> please feel free to comment and suggest improvements .
> 
> Many thanks, Mireille
> 
> 
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Arnold H. Rots                                Chandra X-ray Science Center
Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
60 Garden Street, MS 67                              fax:  +1 617 495 7356
Cambridge, MA 02138                             arots at head.cfa.harvard.edu
USA                                     http://hea-www.harvard.edu/~arots/
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