STC Ontology

Development

I am using Protege 3.0 to develop an OWL-DL ontology of the STC 1.3 schema.

The latest version of the ontology is STC1.3_II.owl, updated in January 2008.

Links

• http://www.ivoa.net/xml/STC/stc-v1.30.xsd - STC 1.3 schema

Questions

1. coordEquinoxType - schema has restriction ("must be string [B,J]"), but class can't have this restriction (would need to be datatype property)
2. why doesn't coordEquinoxtype extend spaceRefFrameType?
3. Not including restrictions involving xs:NC (such as Name and Token) in this draft
4. Should planetaryEphemType be a class with several subclasses or a dataype property with an enumeration?
5. time_unit - other uses of "unit" with timeUnitType should use this?
6. Are astronTimeType-> Timescale and timeFrameType -> TimeScale the same? (looks like it - same list of values).
7. Tempted to make "unit" a class that can restrict to units like "time_unit"; first try keeping unit as datatype property and try restricting within timeCoordinateType class. Seems to work! May need to revisit other enumerations. (NOTE: Timescale is the other one that looks like a class (type typeScaleType) but doesn't have a property to restrict to an enumeration. Ideally would restrict "unit".) "vel_time_unit" kept as datatype property with enumeration.
8. timeUnitType is supposed to be an enumeration, but looks like a class. Add as subclss to unitType, but ignore for now. Same with posUnitType, angleUnitTYpe, velTimeUnitType, spectralUnitType. spectralUnitType - #oneOf{"Hz" "kHz" "MHz" "GHz" "m" "mm" "um" "nm" "Angstrom" "eV" "keV" "MeV" "GeV" "TeV"}. posUnitTYpe #oneOf{"deg" "deg deg m" "deg deg Mpc" "rad" "h" "arcmin" "arcsec" "m" "km" "mm" "AU" "pc" "kpc" "Mpc" "lyr"}. dopplerDefinitionType = another one of these enumeration classes. Put string here til needed. #oneOf{"OPTIC" "RADIO" "RELATIVISTIC"}
9. fitsType - how to restrict class to anyURI?
10. coordFITSColumnsType has same NAMES of properties as astroCoordsType, but they're strings, not classes. Differentiating with lowercase letters for the datatype properties.
11. what about restricted classes? astroCoordSystemType should restrict coordSysType; disinherit hasPixelCoordFrame by setting max cardinality to 0. For now, astroCoordSystemType is sibling of coordSysType. Same with pixelCoordSystemType: restrict maxCardinality to 0 for hasRedshiftFrame, hasSpaceFrame, hasGenericCoordFrame, hasSpectralFrame, hasTimeFrame.
12. What about subclasses that don't even extend the unitType? Such as posAngleReferenceType, timeScaleType?
13. isoTimeTime restricts xs:dateTime; add class but ignore for now. Same for jdTimeType, relocatableOriginTime (enumeration "RELOCATABLE")
14. Why isn't double1Type an stcBaseType?
15. double4Type - why are vector units M1 - M4 doubles instead of double1Types?
16. datatype linearAreaUnit has no white spaces, so "degdegm" instead of "deg deg m".
17. regionAreaType should be double but is class
18. hsOffsetType is parent of Offset - should be double betwen -1.0 and 1.0. Make this a double instead of a class and get ride of hsOffsetType? I can make it a double, but how to restrict range? Max and min values are greyed out in property restriction editor.
19. File is class - how to restrict to anyURI? For now, convert File class to datatype property of anyURI.
20. astroCoordAreaType should restrict coordAreaType, but don't know how to change inherited property hasCoordInterval to hasCoordScalarInterval. Try throwing out hasCoordInterval by restricting maxCardinality to 0 (but in AstroGrid CEA schema, hasn't this previously implied "unlimited"?) Also, does it inherit coord_system_id or not? Same deal with pixelCoordAreaType. Also try pixelSpaceType with maxcardinality =0 to restrict relevant inheritances.
21. TO DO: Have been ignoring cardinality up to now - fix!
22. Have I treated the STCReference attribute group correction by making it a class?
23. anyType is an xs type - OK to keep it as class in ontology, or should I be importing from an xs ontology?
24. Restriction of unitType subclasses isn't quite right since they restrict unit but don't actually list unit as a property
25. Region - several classes haveRegion even though the corresponding Type classes also haveRegion

-- ElizabethAuden - 28 May 2006

* STC1.3.owl: OWL format ontology of STC 1.3