Re: New UCD list

From: Andrea Preite Martinez <andrea.preitemartinez-at-rm.iasf.cnr.it>
Date: Mon, 9 May 2005 17:06:49 +0200

  Dear Jonathan,

> question: I assume that the suggestion I made in Aug 2004 for
"phot.flux.beam"
> should now be handled by "phot.flux;instr.beam" using the new
"instr.beam"
> UCD?
  You're right, that was the idea.

> comment: I applaud the simplification of phot.color. How are you handling
> this in the Vizier tables with more than one color? Adding secondary pairs
of
> "em.*" UCDs?

  Yes, if U-B and V-K are present, we would simply have phot.color;em.opt.U;em.opt.B
phot.color;em.opt.V;em.IR.K

> comment: The UCD desc for 'phot.count' still includes the comment "count
(/s)"
> even though on Oct 19 you agreed on the feedback form that we drop the
"/s".

  Thanks, this will be fixed in version 1.01 of the list.

> comment: I second Alberto's suggestions on homogenization of things like
> resolution.

  Yes, I agree. Anyone opposing the following changes ?

instr.angRes -> pos.resolution (angular resolution) instr.spect.resolution -> spect.resolution (spectral resolution)

> comment: However, On attempting to map the WCS keywords with things like
> arith.1_1, I think this is trying to take UCDs beyond where they should
> go (something I've been accused of myself!). That's what a UTYPE is for,
> to map it to a data model. All the components of cdmatrix are the same
> kind of thing and should have the same ucd.

  I also agree with you.

> concern:
>
> On the comments page I also asked in August-Sept. 2004 for feedback on the
> following proposed UCDs:
> em.veloc.radio

  There are several things at stake with this one. You can now describe velocities
with the following combinations:

  For radial velocities derived from a spectrum:

spect.veloc   -- which can be followed by a word em.* :
spect.veloc;em.opt      or
spect.veloc;em.radio    or
spect.veloc;em.line.HI

...

  For other velocities :
src.veloc (by the way, the definition is wrong in the list! It should not read "radial velocity",
but simply "Velocity").

  You first suggested em.veloc.radio to account for the 2 conventions to derive velocities from spectra (optical and radio conventions). If nobody
ever applies the optical convention to a radio spectrum (or vice versa), then we can live with spect.veloc;em.opt and spect.veloc;em.radio   What do you think?

> meta.curation

  What about having a few specific words to describe the elements of VOResource metadata:

meta.entity (or meta.identity and meta.organization) meta.version
...

> phys.energy-density

  Yes, but spelled phys.energyDensity ?

> src.net

  You suggested three words to distinguish total source flux, background flux,
and net source flux. I don't feel comfortable with src.net, because net values
should be the default...
  The background could be described by a qualifier, e.g. renaming instr.background
to stat.background.
  "Total" is too general a word. Can you suggest a more specific word to describe source+background? Would this be the same as aperture photometry
in the optical (i.e. total flux measured within some radius).

> I also still
> think that it would be a good idea if new UCDs were circulated for
> comment to the UCD WG "board" before the web page was updated, the
> process still seems a bit opaque and over-centralized.

  I think the role of the Kyoto session will also be to formalize the existence of the board. Emails like yours contribute to make the process less opaque!

> (by the way, the automated emails we get with "A suggestion has been made
for
> a new UCD" would I think be much more useful if the text of the suggestion
> was included, removing one step in the process, since I have the
impression
> few WG members have been responding to them).

  Okay, it can be done!

Andrea.


Andrea Preite Martinez                  andrea-at-rm.iasf.cnr.it
Istituto di Astrofisica Spaziale        Tel.:+39.06.4993.4641
Area di Ricerca di Tor Vergata          Fax.:+39.06.2066.0188
Via del Fosso del Cavaliere 100         Cell:+39.339.3817355
00133 Roma
Received on 2005-05-09Z15:07:16