Memo: Applications using STC   - A. Rots, 2007 Apr 12

1. VOEvent
The WhereWhen information of a VOEvent uses the ObsDataLocation
construct from STC to indicate the spatial and temporal metadata of
the event. That description is complete and unambiguous.
VOEvent recognizes a limited collection of standard coordinate
systems.
See: http://ivoa.net/Documents/latest/VOEvent.html

2. JHU Footprint Service
The footprint service developed at JHU and used for SDSS and HLA
deploys STC regions and coordinate positions for describing footprints
and search regions. It represents a complete implementation of STC
regions and provides a complete set of operative functions.
See: http://voservices.net/footprint
Coordinate transformation are not supported, although it would not be
difficult to add.

3. Registry
The Coverage component of the Registry's resource description is
expressed through STC metadata. These descriptions are complete and
unambiguous. An issue arising from the concatenation of documents, as
performed by registry services, appears to be headed for imminent
resolution; otherwise there is an acceptable work-around. It should be
stressed that this is not a specific STC issue, but the general
problem of handling unambiguous associations between elements when
concatenating documents.
See: http://ivoa.net/Documents/latest/RM.html

4. David Berry's prototype
David Berry implemented a prototype coordinate transformation service
for STC version 1.20.
Although this service is not operative for the present version, it
demonstrates that the coordinate system metadata in STC pass the test
of allowing coordinate transformations to be executed unambiguously.
See: http://www.starlink.ac.uk/~dsb/ast/ast.html#stc_demo

5. Examples
Ten validated sample documents show that the schema meets its
requirements of being able to represent the coordinate metadata for a
wide range of applications.

See also my STC web page http://hea-www.harvard.edu/~arots/nvometa/STC/


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Arnold H. Rots                                Chandra X-ray Science Center
Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
60 Garden Street, MS 67                              fax:  +1 617 495 7356
Cambridge, MA 02138                             arots@head.cfa.harvard.edu
USA                                     http://hea-www.harvard.edu/~arots/
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