VOEvent used for solar knowledge base
Rob Seaman
seaman at noao.edu
Tue Jul 17 15:32:50 PDT 2007
Hi Elizabeth,
> I'd like to highlight a new solar use case for the VOEvent schema.
> Lockheed Martin is building a heliophysics features and event
> knowledge
> base (http://www.lmsal.com/helio-informatics/hpkb/). The
> knowledgebase is
> built up as solar events are identified, described as VOEvent packets
> with the addition of <lmsal:*> tags, and submitted to the
> knowledgebase.
As some of us discussed a few weeks back, this seems like a very cool
application that we are eager to support. I don't believe the
standard has to evolve to permit these packets (once we iron out some
issues), just the schema.
> The VOEvent schema already imports the IVOA's STC schema - can
> additional
> schemas be imported as well so that VOEvent packets can include
> customized
> elements like the <lmsal:*> tags while still conforming to the
> VOEvent schema?
I personally think this is a good idea. Do you have a revised
VOEvent schema for the working group to consider?
> I've attached a sample XML file (describing a coronal loop)
> generated by
> the SolarSoft vobs/ontology module's struct4export and export_event
> procedures. You may notice a <Group> placed inside <WhereWhen> that
> describes the loop's placement on the Sun. The Lockheed group is
> amenable
> to moving such groups to <What>.
I think this would be preferred. <WhereWhen> has enough work to do
with STC. BTW, I'm pleased to see an example of solar STC usage,
demonstrating the versatility of the IVOA space-time model.
Additional comments are interspersed with the sample XML.
Rob
------
> <?xml version="1.0" encoding="UTF-8" ?>
> <voe:VOEvent ivorn="Reserved for KB archivist: KB entry identifier"
> role="observation" version="1.1" xmlns:voe="http://www.ivoa.net/xml/
> VOEvent/v1.1" xmlns:lmsal="http://sot.lmsal.com/solarb/"
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> xsi:schemaLocation="http://www.ivoa.net/xml/VOEvent/v1.1 http://
> www.ivoa.net/xml/VOEvent/VOEvent-v1.1.xsd">
I'll leave precision pedantry to others, but you would want to
namespace STC, too - either here or in <WhereWhen>.
I presume actual IVORNs would be used. Have you considered how the
knowledgebase would interact with IVOA registries?
> <Who>
> <!-- Data pertaining to curation -->
> <Name>Reserved for KB archivist: KB entry made by</Name>
> <AuthorIVORN>Reserved for KB archivist: URL to suppl. info.</
> AuthorIVORN>
> <Date>2007/6/19 3:26:24</Date>
> </Who>
The <Date> should be ISO-8601 per the standard (http://ivoa.net/
Documents/latest/VOEvent.html).
> <What>
> <!-- Data about what was measured/observed. -->
> <Group name="Loop_required">
> <Param name="EVENT_NPIXELS" value="59"/>
> <Param name="EVENT_PIXELUNIT" value="0.5 arcseconds"/>
> </Group>
> </What>
Reasonable usage. You might want to consider the distinction between
the name of a group and its type. "Loop_required" sounds like a type
to me. I'm a bit bemused by the question of appropriate "PIXELUNIT"
usage. A <Param> can have a unit as well as a ucd (and maybe a utype
in the future). Not sure what the best expression is here.
Comments are ok, but you might consider whether these would better be
expressed as <Descriptions> - probably not for these simple examples,
but such annotations are appropriate for users as well as programmers.
> <WhereWhen>
> <!-- Data pertaining to when and where something occured -->
> <ObservationLocation id="EIT">
> <AstroCoords coord_system_id="UTC-HPC-TOPO">
> <Time>
>
> <TimeInterval>1999-07-19T13:48:10.092,1999-07-19T13:48:23.596</
> TimeInterval>
> </Time>
>
> <Position2D unit="arcsec">
> <Value2>
> <C1>460.000</C1>
> <C2>955.000</C2>
> </Value2>
> <Error2>
> <C1>-1.00000</C1>
> <C2>-1.00000</C2>
> </Error2>
> </Position2D>
> <SpatialRegion>
> <Region>Box</Region>
> <!-- Coordinates of lower-left corner of
> bounding box -->
> <Value2>
> <C1>451.000</C1>
> <C2>939.000</C2>
> </Value2>
> <!-- Coordinates of upper-right corner of
> bounding box -->
> <Value2>
> <C1>460.000</C1>
> <C2>955.000</C2>
> </Value2>
> </SpatialRegion>
> </AstroCoords>
> </ObservationLocation>
Since you didn't namespace STC, I suspect this won't actually validate.
> <Group name="Loop_required">
> <Param name="CHAINCODETYPE" value="unknown"/>
> <Param name="SKEL_CHAINCODE" value="unknown"/>
> <Param name="SKEL_CURVATURE" value="-1.00000"/>
> <Param name="SKEL_NSTEPS" value="-1"/>
> <Param name="SKEL_STARTC1" value="-1.00000"/>
> <Param name="SKEL_STARTC2" value="-1.00000"/>
> </Group>
> </WhereWhen>
Perhaps you can explain in more detail why this might be more
appropriate for <WhereWhen>, rather than for <What>. If there is no
strong justification, please relocate to the <What> element.
> <How>
> <!-- Data pertaining to how the feature/event detection was
> performed -->
> <lmsal:data>
> <lmsal:OBS_ChannelID>EIT 195</lmsal:OBS_ChannelID>
> <lmsal:OBS_Instrument>EIT</lmsal:OBS_Instrument>
> <lmsal:OBS_MeanWavel>195.000</lmsal:OBS_MeanWavel>
> <lmsal:OBS_WavelUnit>Angstroms</lmsal:OBS_WavelUnit>
> </lmsal:data>
> <lmsal:method>
> <lmsal:FRM_Contact>ms2 at mssl.ucl.ac.uk</lmsal:FRM_Contact>
> <lmsal:FRM_DateRun>2007/6/19 3:26:24</lmsal:FRM_DateRun>
> <lmsal:FRM_HumanFlag>no</lmsal:FRM_HumanFlag>
> <lmsal:FRM_Identifier>Mike Smith</lmsal:FRM_Identifier>
> <lmsal:FRM_Institute>MSSL</lmsal:FRM_Institute>
> <lmsal:FRM_Name>LoopRecog</lmsal:FRM_Name>
> <lmsal:FRM_ParamSet>inputFile, sigma,
> minimumContourPoints, OutputFile</lmsal:FRM_ParamSet>
> </lmsal:method>
> </How>
The original notion was to embed <References> to external RTML
documents. The above seems reasonable usage, however, and if so, we
would likely also want to permit embedded RTML. I would like to
initially entertain the idea that such imported schema would be
limited to specific elements, not written across the entire packet.
That is, STC would be restricted to <WhereWhen> and lmsal and rtml
would be restricted to <How>. Comments?
> <Why>
> <Inference probability="Inf"/>
> <Concept>Loop</Concept>
> <lmsal:EVENT_TYPE>LP: Loop</lmsal:EVENT_TYPE>
> </Why>
I think better yet would be for the lmsal event types to inform the
evolution of native VO vocabulary lists, such as a VOEvent UCD
namespace. Perhaps Rick can comment.
The value of the probability attribute should be a floating point
number bounded between 0.0 and 1.0.
> <Reference name="FRM_URL" uri="http://www.mssl.ucl.ac.uk/twiki/
> bin/view/SDO/CoronalLoopDeployment"/>
You might include a meaningful <Description> corresponding to this
<Reference>.
> </voe:VOEvent>
The name "knowledgebase" implies interesting interdependencies
between the packets contained within. I'm wondering if the VOEvent
<Citations> element could be particularly useful for this purpose.
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