DM work package : Utypes definition and syntax

Site under re construction

*This topic is under the Data model pages but also addressed in the TCG Topic page : http://www.ivoa.net/cgi-bin/twiki/bin/view/IVOA/TCGTopicsUtypes

What are Utypes for

Utypes are strings that we define in the VO to be able to represent and identify which role plays a specific piece of metadata
Ex: astrometry statistical error = 0.02 arcsec can be represented in the VO by : char:Spatial.Accuracy.StatError.Refval
and verified by the XML schema derived from the Characterisation Data 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
2. Browse the Utype list and its documentation to select the appropriate Utype for your metadata description _Ex : for a Fits image : FITS keyword RESOL to map RefVal Characterisation Data Model _ for a Fits simple spectrum : FITS keyword SPECRES to map RefVal
3. Check wether all mandatory Utypes are filled in .

If you publish your data with Characterisation , you can use the CAMEA VO Tool (http://eurovotech.org/twiki/bin/view/VOTech/CharacEditorTool) to check the Utype assignation, and see how much your description is Characterisation DM compliant.