A modest proposal for VOEvent

[Roy Williams]

Perhaps we can use the existing VOEvent structure, with no need to add 
any extra schema (see below). The Group type (eg ="ephemeris") tells the 
software what Params to expect inside. Everything can be represented 
with what we already have!

Roy

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<What>
<Group name="Pluto" type="orbit">
 <Param name="q"             unit="AU"  dataType="float" value="123" />
 <Param name="e"                        dataType="float" value="123" />
 <Param name="i"             unit="deg" dataType="float" value="123" />
 <Param name="node"          unit="deg" dataType="float" value="123" />
 <Param name="time_peri_MJD" unit="MJD" dataType="float" value="123" />
 <Param name="arg_peri"      unit="deg" dataType="float" value="123" />
 <Param name="epoch"         unit="MJD" dataType="float" value="123" />
 <Param name="src" value="1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 
19 20 21" />
</Group>

Then we would add geocentric ephemeris

<Group name="E012" type="ephemeris">
 <Param name="ephem_type"                             value="geocentric"/>
 <Param name="ra"         unit="deg" dataType="float" value="123" />
 <Param name="dec"        unit="deg" dataType="float" value="123" />
 <Param name="mjd"        unit="day" dataType="float" value="123" />
</ephemeris>

And the detections used to derive the orbit

<Group name="D023" type="detections">
 <Param name="ra"  unit="deg" dataType="float" value="123" />
 <Param name="dec" unit="deg" dataType="float" value="123" />
 <Param name="mjd" unit="day" dataType="float" value="123" />
 <Param name="obscode"                         value="123" />
</Group>
</What>
-- 

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