T0 : extensions to em, obs, spect, instr

[Andrea Preite Martinez]

Quoting Jonathan McDowell :

> Rick Hessman proposed a number of UCDs (May 30) and I wanted to 
> comment on them.
> One was
>  spect.cont    spectral continuum
> I endorse adding this, it's very useful for my own data.

If you mean that  spect.cont is a sort of flux per unit something, than
it'll be better to wait for a revision of the fluxDensity word

> So here's my proposal for Rick's list, in which proposed new UCDs
> are marked by a *  (sort of the paleolinguistics convention of
> marking hypothetical word forms with a *).
>
>  Rick                                   Jonathan
>  phys.grav-wave/em.grav-wave            *phys.wave.gravitational
>  phys.particle.neutrino/em.neutrino     *phys.particle.neutrino
>  instr.calib                 *obs.calib  [Calibration observation]

Yes, we could introduce the three sub-trees:
S | phys.wave.*
S | phys.particle.*  (starting for the already present electron)
S | obs.calib(.*)

A few comments on the following list:

>  phot.calib                   obs.image;*obs.calib;phot.flux
>        [It's an image; it's for calibration; what are we calibrating - flux.]
>                               spect;*obs.calib;phot.flux
>        [or, it's a spectrum...]
>  obs.calib.dome-flat          
> obs.image;obs.calib;*instr.det.flat;*instr.tel.dome
>        [We're calibrating the flatness of the detector; we're using 
> the dome to do it]
>  obs.calib.flux               obs.image;*obs.calib;phot.flux
>  obs.calib.freq               spect;*obs.calib;em.freq
>        [It's a spectrum; it's for calibration; we're calibrating freq]
>  obs.calib.guide-star         meta.id;*obs.calib;*pos.astrometry
>        [If this is the name of the guide star used..]
>  obs.calib.phot    [What's the difference with obs.calib.flux?]
>  obs.calib.pos                obs.image;*obs.calib;*pos.astrometry  (?)
>  obs.calib.sky-flat           obs.image;obs.calib;*instr.det.flat
>  obs.calib.slit-mask          *instr.spect.slit
>  obs.calib.spect              spect;*obs.calib;em.wl
>       [If you mean by this an arc spectrum; what diff from obs.calib.wl?]
>  obs.calib.veloc              spect;*obs.calib;src.veloc
>  obs.calib.wl                 spect;*obs.calib;em.wl
>  phot.calib.flux              [same as obs.calib.flux?]
>  phot.calib.mag               *obs.calib;em.opt.B   (etc.)
>  pos.calib                    *obs.calib;pos
>  spect.calib                  spect;*obs.calib
>  spect.calib.wl               spect;*obs.calib;em.wl
>  spect.calib.freq             spect;*obs.calib;em.freq

1. the order is inverted: e.g.
obs.image;*obs.calib;phot.flux   ==> phot.flux;obs.calib
spect;*obs.calib;src.veloc       ==> src.veloc;obs.calib
*obs.calib;em.opt.B              ==> phot.mag;em.opt.B;obs.calib

The same for Rick's suggestions:
instr/tel;optics.focallength     ==> optics.focallength;instr/tel

2. We have to maintain UCD-words, not UCDs

3. Saying: [It's an image; it's for calibration; what are we calibrating -
flux.] means that you are probably describing a detaset, so an alternative
description could be: [name (or url, or ...) of an image used for
flux-calibrating other images of raw data]
that could translate into :
meta.id;obs.image;obs.calib

We probably need a deeper discussion before introducing new trees.
I agree with Jonathan: let's move quickly from WD to PR, and continue at the
same time the discussion on new words, object types, events, etc...

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
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