STC for VOEvent Arnold Rots CfA/SAO
VOEvent II - Tucson: STC2 STCLite …
VOEvent II - Tucson: STC3 STCLite … … is dead
VOEvent II - Tucson: STC4 STC Basics Comprehensive metadata specification of the volume in coordinate space taken up by a particular data product (including telescopes) Intertwined coordinates: –Time –Space –Spectral –Redshift/Doppler
VOEvent II - Tucson: STC5 STC Basics (requirements) Complete Internally consistent –Cover a multitude of coordinate systems: Celestial (equatorial, galactic, …) Cartesian Geographic Solar/planetary Detector coordinates Unit sphere …
VOEvent II - Tucson: STC6 STC Basics (components) Coordinate system –Coordinate frames Reference frame Reference position (origin) Coordinates Values Errors … Coordinate volume Regions allow any shape to be specified
VOEvent II - Tucson: STC7 STC for Observations Where were you looking? –Time, space (direction), (ν, λ, E), (z) –Coordinate system – reference frames –Position, errors, (FOV) Where were you when you were looking? –Geographic position –Spacecraft ephemeris
VOEvent II - Tucson: STC8 STC-X Referencing Promote standardization XInclude –Point to a file –Formally requires the link to be substituted by the entire file contents XLink –Point to anything; e.g., an element in a document –Client decides what to do with it (if anything)
VOEvent II - Tucson: STC9 STC Base Type Optional Xlink attributes: type, href –type=simple href= Optional attribute idref –reference to another element in the same document Optional attribute id –Allowing the element to be referenced Optional contents
VOEvent II - Tucson: STC10 WhereWhen Example <ObservatoryLocation id="MyObservatory" xlink:type="simple" xlink:href=ivo://STClib/Observatories.xml#MyObservatory"/> <AstroCoordSystem id="UTC-FK5-TOPO" xlink:type="simple" xlink:href=ivo://STClib/AstroCoordSystems.xml#UTC-FK5-TOPO"/> T23:59:
VOEvent II - Tucson: STC11 Add Diamond-shaped Region
VOEvent II - Tucson: STC12 Empty Elements What if an element is empty (now allowed) or absent (may be allowed)? –It is UNKNOWN What does that mean? –It is up to the client to either reject or assume a sensible default i.e., sensible is in the eye of the beholder If you dont want your clients guessing, be specific