The State of VOEvent Rob Seaman, NOAO/DPP IVOA InterOp, Trieste 22 May 2008.

The State of VOEvent

Rob Seaman, NOAO/DPP

IVOA InterOp, Trieste

22 May 2008

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Today’s agenda:

V2.0, time series, orbits, and all that – Rob Seaman

Portfolios for Event sharing & evaluation – Matthew Graham

VO-GCN (Let the revolution begin!) – Scott Barthelmy

Resisting the forces of (unnecessary) change – Alasdair Allen

Key issues are: Embracing:Vocabularies semantically aware science

Signatures data integrity / per stream DQA

External schemata outside communities

Time series the larger time domain

Orbital elements the workflow

Registry the VO vision

Tweaks the real world

Vocabularies – <What> & <Why>

As at Monday’s excellent session (& next)

Seems well in hand

No modification of standard needed<Concept> can support controlled vocab.<Param> can contain anything

When new vocabulary is ready, just use explicitly

Signatures – envelope

As at Wednesday’s excellent session

Don’t include signature in <VOEvent>

Pick one or the other technology, or both and let the market decide

Encourage (not require) wide usage

Encourage (demand?) broker support

External schemata – <What>

Already in useHeliophysics Knowledgebase

Must be compatible with IVOA usage

Schema must support this

Registry must handle this

A small change may be needed to the language of the standard

Time series vs. orbital elements

Seem similar, but very different

VOEvent is a report of observation(s) of transient phenomena,“with the implication that timely follow-up is being requested”

A time series expresses the previous sky<What> was the behavior (thus not STC)

An orbit predicts future sky behavior<WhereWhen> to look next time (STC)

Time series – <What>

Spectral Data Model

vs. “Napkin representation”

WG discussed several variations after Hotwired workshop

Make as simple as possible to start

Can elaborate in later revisions

Napkinrepresentation

What we signed at Hotwired in Tucson, June 2007

Time series example (per Roy & Al)

<TimeSeries type="sed:Segment" version="0.1">

<Meta></Meta>

<Data>

<Row number="1">

<Time unit="day">1305.65557</Time>

<TimeExtent unit="s">30.00002</TimeExtent>

<Flux unit="mag">7.808</Flux> <FluxErr unit="mag">0.012212</FluxErr>

</Row>

<Row number="2">

<Time unit="day">1305.66351</Time>



</Row>

<Row number="3">

<Time unit="day">1305.6697<Time>



</Row>

</Data>

</TimeSeries>

Time series metadata

<Meta>

<PARAM name="Model" ucd="meta.id" utype="sed:DataModel" value="SED-0.95"/>

<PARAM name="System" ucd="frame.pos.system" utype="sed:Segment.Frame.Sky.Type" value="FK5"/>

<PARAM name="Equinox" ucd="time.equinox;pos.eq" utype="sed:Segment.Frame.Sky.Equinox" value="2000.0"/>

<GROUP utype="sed:Segment.Frame.Time">

<PARAM name="TimeType" ucd="time.scale" utype="sed:Segment.Frame.Time.Type" value="MJD"/>

<PARAM name="TimeZero" ucd="time;arith.zp" utype="sed:Segment.Frame.Time.Zero" value="51544.0"/>

<PARAM name="TimeRefPos" ucd="time.scale" utype="sed:Segment.Frame.Time.RefPos" value="BARYCENTRIC"/>

</GROUP>

<GROUP utype="sed:Segment.Frame.SpectralCoord">

<PARAM name="SpectralRefPos" ucd="frame.em.system" utype="sed:Segment.Frame.SpectralCoord.RefPos" value="BARYCENTER"/>

</GROUP>

</Meta>

Time series metadata, #2

<GROUP utype="sed:Segment.Coverage.Location">

<PARAM name="SkyPos" unit="deg" ucd="pos.eq" utype="sed:Segment.Coverage.Location.Sky.Value" value="7.47722483 8.80624972"/>

<PARAM name="TimeObs" ucd="time.epoch" utype="sed:Segment.Coverage.Location.Time.Value" value="1305.6637641802704"/>

<PARAM name="Instbandpass" ucd="instr.bandpass" utype="sed:Segment.Coverage.Location.SpectralCoord.Value" value="V"/>

</GROUP>

<GROUP utype="sed:Segment.Coverage.Extent">

<PARAM name="SkyExtent" unit="deg" ucd="instr.fov" utype="sed:Segment.Coverage.Extent.Sky" value="5"/>

<PARAM name="SpectralExtent" ucd="instr.bandwidth" utype="sed:Segment.Coverage.Extent.Spectral" value="Optical"/>

</GROUP>

<GROUP utype="sed:Segment.Coverage.Region">

<PARAM name="TimeStart" ucd="time.expo.start" utype="sed:Segment.Coverage.Region.Time.Start" value="1305.6530292210973"/>

<PARAM name="TimeEnd" ucd="time.expo.end" utype="sed:Segment.Coverage.Region.Time.End" value="1305.6744991394435"/>

</GROUP>

Time series metadata, #3

<GROUP utype="sed:Segment.Curation">

<PARAM name="Publisher" ucd="meta.curation" utype="sed:Segment.Curation.Publisher" value="INTA/LAEFF"/>

<PARAM name="PubID" ucd="meta.ref.url;meta.curation" utype="sed:Segment.Curation.PubID" value="http://sdc.laeff.inta.es:80/omc/" />

<PARAM name="Logo" ucd="meta.ref.url" utype="sed:Segment.Curation.Logo" value="http://sdc.laeff.inta.es/omc/images/laeff-logcab-02.jpg"/>

<PARAM name="Contact" ucd="meta.bib.author;meta.curation" utype="sed:Segment.Curation.Contact.Name" value="Enrique Solano"/>

<PARAM name="email" ucd="meta.ref.url;meta.email" utype="sed:Segment.Curation.ContactEmail" value="[email protected]"/>

</GROUP>

<GROUP utype="sed:Segment.DataID">

<PARAM name="Title" ucd="meta.id;meta.dataset" utype="sed:Segment.DataID.DatasetID" value="OMC Light Curve. Target: AG+0849"/>

<PARAM name="Instrument" ucd="inst.id" utype="sed:Segment.DataID.Instrument" value="INTEGRAL/OMC"/>

<PARAM name="Creator" ucd="meta.curation.creator" utype="sed:Segment.DataID.Creator" value="INTA/LAEFF"/>

</GROUP>

<PARAM name="Object" ucd="meta.id;src" utype="sed:Segment.Target.Name" value="AG+0849" />

<PARAM name="Coord" unit="nm" ucd="em.wl" utype="sed:Segment.Points.SpectralCoord.Value" value="550"/>

<PARAM name="Calibration" utype="sed:Segment.Points.Flux.Calibration" value="CALIBRATED"/>

Time series questions

Chain of packets or

embedded in single packet?<Params> or extend the schema?

or both?VOEvent specific or general VO DM?

or both?If so, SDM or STC?

A time series is an aggregate object

multiple instrumentsjoint curationcomplex footprint in time

and in space for moving objectsrequires matched calibrationsobject(s), not detections

must build associations

Orbital elements – <WhereWhen>

A targeting ephemeris

If STC can gracefully handle this, it will go a long way to resolving STC status in VO

Orbit example

<Orbit>

<a unit="AU">1.5610990</a>

<e>0.4412673</e>

7.21282

<Node unit="deg">353.14214</Node>

<Aop unit="deg">265.00121</Aop>

<M unit="deg">319.73232</M>

<T><ISOTime>1998-03-08T00:00:00</ISOTime></T>

</Orbit>

Orbit example, #2

<AstroCoords coord_system_id="TDB-ECLIPTIC-BARY"> <Time>

<TimeInstant><ISOTime>1998-03-08T00:00:00</ISOTime></TimeInstant>

</Time>

<Orbit><a unit="AU">1.5610990</a>

<e>0.4412673</e>

7.21282



<M unit="deg">319.73232</M>


</Orbit>

</AstroCoords>

Orbit example, #3

<CatalogEntryLocation xmlns="http://www.ivoa.net/xml/STC/stc-v1.30.xsd”

xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://www.ivoa.net/xml/STC/stc-v1.30.xsd http://www.ivoa.net/xml/STC/stc-v1.30.xsd">

<AstroCoordSystem xsi:nil="true" xlink:type="simple"

xlink:href="ivo://STClib/CoordSys#TDB-ECLIPTIC-BARY"

id="TDB-ECLIPTIC-BARY"/>

<AstroCoords coord_system_id="TDB-ECLIPTIC-BARY">

<Time>


</Time>

<Orbit>

<a unit="AU">1.5610990</a>

<e>0.4412673</e>

7.21282



<M unit="deg">319.73232</M>


</Orbit>

</AstroCoords>

Alternate orbit representations

STC provides options:orbital elementsPole and pericenter vectorsRA, Decs at intervals

Pole and vector notation:

<AstroCoords coord_system_id="TDB-UNIT-ECLIPTIC-BARY"><Time>

<TimeInstant><ISOTime>1998-03-08T00:00:00</ISOTime></TimeInstant></Time><Position3D>

<Name>P</Name><Value3>

<C1>-0.18756117</C1><C2>-0.84401876</C2><C3>-0.50243968</C3></Value3>

</Position3D>

</AstroCoords>

<AstroCoords coord_system_id="TDB-UNIT-ECLIPTIC-BARY" ><Time>

<TimeInstant><ISOTime>1998-03-08T00:00:00</ISOTime></TimeInstant></Time><Position3D>

<Name>Q</Name><Value3>

<C1>+0.98213469</C1><C2>-0.16897175</C2><C3>-0.08282516</C3></Value3>

</Position3D>

</AstroCoords>

Discrete pointings

<AstroCoords coord_system_id="TDB-ICRS-BARY" >

<Time>


</Time>

<Position2D unit="deg">

<Value2><C1>179.52</C1><C2>-3.933</C2></Value2>

</Position2D>

</AstroCoords>


<Time>


</Time>


<Value2><C1>176.53</C1><C2>-7.713</C2></Value2>

</Position2D>

</AstroCoords>


<Time>


</Time>


<Value2><C1>171.91</C1><C2>-13.343</C2></Value2>

</Position2D>

</AstroCoords>

Minor tweaks?

Permit <Reference type=“kml”>

Any others?

Registering VOEvent assets

As discussed Wednesday (Thanks Roy!)

VOEventStreamScientifically coherent entity

VOEventService or VOEventServer?Logistically clustered functionality

Provides simple “schema” for <Param>

Work products

1) v2.0 standard documentv2.0 schema

2) VOEvent vocabulary (or -ies)

3) VOEvent registry documentRegistry schema

4) Pilot signing technologies

5) Transport document

6) User guide

Future events

Finalize v2.0 by the Fall InterOpHTN coordination (HTN IV)ADASS tutorial (or BoF?)VOEvent IV (Spring 2009?)Activities @ IAU GA 2009?Time domain astronomy conference @

SPIE 2010?Many other activities continue apace

Agenda:

V2.0, time series, orbits, and all that – Rob Seaman

Portfolios for Event sharing & evaluation – Matthew Graham

VO-GCN (Let the revolution begin!) – Scott Barthelmy

Resisting the forces of (unnecessary) change – Alasdair Allen

The State of VOEvent Rob Seaman, NOAO/DPP IVOA InterOp, Trieste 22 May 2008.

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Transcript of The State of VOEvent Rob Seaman, NOAO/DPP IVOA InterOp, Trieste 22 May 2008.