Transcript VOTable discussions  Concerns about how units  date/time (ISO8601) -- no new datatype!  sexagesimal are expressed in VOTable and other VO components  need common.

VOTable discussions
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Concerns about how
units
 date/time (ISO8601) -- no new datatype!
 sexagesimal
are expressed in VOTable and other VO components
 need common solutions in VO components!
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Concerns about VOTable recursivity (kept)
Concerns about conservation of VOTable
structures in applications (TOPcat)
 will be fixed
The utype question
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incorporated in VOTable 1.1
(VOTable is a serialization of parameters which may
originate from any part of the VO)
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Role = give a fully detailed meaning by a
reference to an external data model, e.g.
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systems in which values are expressed (photometry)
reference frames used for space / time / etc (STC)
(ucd = broad semantics)
Used in other VO components (DAL), look for
generic and common solutions.
utype example for Regions
(static model)
<stc:Circle>
<stc:Center unit="deg">
<stc:C1>233.737917</stc:C1>
<stc:C2>23.503330</stc:C2>
</stc:Center>
<stc:Radius pos_unit="arcsec">12.0</stc:Radius>
</stc:Circle>
<FIELD ID="Col1" name="cRA"
utype="stc:Circle.Center.C1" ucd="pos.eq.ra"
unit="deg" datatype="double" />
<FIELD ID="Col2" name="cDec"
utype="stc:Circle.Center.C2" ucd="pos.eq.dec"
unit="deg" datatype="double" />
<PARAM name="targetRadius"
utype="stc:Circle.Radius" ucd="pos.angDistance"
datatype="double" unit="arcsec" value="12.0"/>
utype example for Regions
(dynamic model)
<stc:Polygon>
<stc:Vertex>
<stc:Position>
<stc:C1>233.737917</stc:C1>
<GROUP name="myPolygon" utype="stc:Polygon">
<stc:C2>23.503330</stc:C2>
</stc:Position>
<FIELDref ref="vert1">
</stc:Vertex>
<FIELDref ref="vert2">
<stc:Vertex>
<FIELDref ref="vert3">
<stc:Position> ...
</GROUP>
... ... ...
<FIELD ID="Vert1" name="point1"
</stc:Polygon>
utype="stc:Polygon.Vertex" ucd="pos.eq"
unit="deg" arraysize="2" datatype="double" />
<FIELD ID="Vert2" name="point2"
utype="stc:Polygon.Vertex" ucd="pos.eq"
unit="deg" arraysize="2" datatype="double" />
[...]
STC reference via utype
<GROUP ucd="pos">
<PARAM utype="stc:AstroCoordSystem.SpaceFrame.Name"
datatype="char" arraysize="*"
name="coosys" value="ICRS" />
<FIELDref ref="col1"/>
<FIELDref ref="col2"/>
<PARAM name="Epoch"
utype="stc:AstroCoordSystem.SpaceFrame.Epoch"
datatype="double"
value="1991.25" />
</GROUP>
<FIELD ID="col1" name="RA" datatype="double"
utype="stc:AstroCoords.Position2D.C1"
unit="deg" />
<FIELD ID="col2" name="Dec" datatype="double"
utype="stc:AstroCoords.Position2D.C2"
unit="deg" />
VOTable Roadmap
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Referencing STC via utype
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proposal (Jonathan)  June 2006
discussion of proposals (July -- August)
take a decision at next IVOA in September 2007
Toward a new schema (to be discussed in
September)
details about utype conventions and
recommended usage
 deprecate COOSYS
 rationalized (closer to Java usage)
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