Utypes < IVOA

---+ DM work package : Utypes definition and syntax

Work is currently taking place in UtypesTigerTeam.

Last iterations on the definitions (presentations @ interop meetings)
   * at Interop May 2010 in Victoria [[http://wiki.ivoa.net/internal/IVOA/InterOpMay2010DMDAL/UtypesIntheIVOA.pdf][UtypesIntheIVOA.pdf]]
   * at Interop May 2011 in Napoli [[http://wiki.ivoa.net/internal/IVOA/DAL-InteropMay2011/UtypesIntheIVOA-2011.pdf][UtypesIntheIVOA-2011.pdf]]
   * Utypes session at Interop Oct 2011 in Pune [[http://wiki.ivoa.net/twiki/bin/view/IVOA/InterOpOct2011DM]]
This topic is under the Data model pages but also addressed in the TCG Topic page : ?? IVOA.TCGTopicsUtypes

---+++ What are Utypes for

Utypes are names that we can attach to a piece of metadata in order to point to the same concept expressed in a VO data model. 
%BR% Ex: =astrometry statistical error = 0.02 arcsec=

This metadata can be represented in the VO using the Characterisation data model by : ==char:Spatial.Accuracy.StatError.Refval==

If we associate "astrometry statistical error" with this utype, we can derive various properties like:

   1 the concept of astrometrical error is the same as the one described in the model.
   1 This concept relies on accuracy along the spatial axis.
   1 If we provide a value with this utype, it is stored in the same type as the data model element and if mentionned in the restricted units defined by the model.

---+++ How can I find which Utype is relevant for my data collection
   1 Select an IVOA data model to which you want to be compliant. Ex : Characterisation Data Model
   1 Browse the Utype list and its documentation to select the appropriate Utype list for your metadata description
   1 Check wether all mandatory Utypes are filled in .
   $ Examples: - For a Fits image : FITS keyword RESOL will map ==SpatialAxis.Resolution.RefVal== in the Characterisation Data Model utypes list

- For a Fits simple spectrum : FITS keyword SPECTRES will map ==SpectralAxis.Resolution.RefVal==

If you publish your data with !CharacterisationDM-v1.11 , you can use the CAMEA VO Tool (http://eurovotech.org/twiki/bin/view/VOTech/CharacEditorTool) to check the Utype assignation, and verify if your description is compliant to this model.

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   * [[%ATTACHURL%/WD-Utypes-0.3-20090522.pdf][WD-Utypes-0.3-20090522.pdf]]: Utype preliminary WD

Attachments

Topic attachments
I	Attachment	History	Action	Size	Date	Who	Comment
xml	ObsTAPQueryExample.xml	r1	manage	18.6 K	2012-05-23 - 13:52	MireilleLouys	example of Query response from ObsTAP
xml	PhotDMRegistryRecord.xml	r2 r1	manage	2.5 K	2012-05-23 - 15:28	MireilleLouys	Example of IVOA DM registration record
zip	Utypedraft2012.zip	r2 r1	manage	885.5 K	2012-05-23 - 15:36	MireilleLouys	tex and images for Utype draft
pdf	WD-Utypes-0.3-20090522.pdf	r1	manage	547.0 K	2009-05-25 - 20:31	MireilleLouys	Utype preliminary WD
pdf	WD-Utypes-0.4-20091107.pdf	r1	manage	580.4 K	2009-11-09 - 09:04	MireilleLouys
tex	WD-Utypes-0.4-20091107.tex	r1	manage	34.8 K	2011-10-20 - 09:53	MireilleLouys	tex version
pdf	WD-Utypes-0.7-20120521.pdf	r1	manage	647.3 K	2012-05-23 - 14:22	MireilleLouys	Utype draft Mai 2012
pdf	WD-Utypes-0.7-20120523.pdf	r1	manage	647.3 K	2012-05-23 - 15:38	MireilleLouys	Utype draft Mai 2012
html	note-utype-draft1.5.html	r1	manage	34.1 K	2007-01-28 - 13:51	NormanGray	Draft Note on UTypes
pdf	utype-extra-meeting.pdf	r1	manage	273.7 K	2011-11-15 - 19:05	OmarLaurino

This topic: IVOA > WebHome > IvoaDataModel > Utypes
Topic revision: r17 - 2012-10-23 - MarkusDemleitner