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 : ?? 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 list for your metadata description
3. Check wether all mandatory Utypes are filled in .

Examples

- For a Fits image : FITS keyword RESOL to map Spatial.Resolution.RefVal in the Characterisation Data Model utypes list

- For a Fits simple spectrum : FITS keyword SPECTRES to map Spectral.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.