Meeting Notes from last weeks IF meeting

Attendance: Hans Jespersen, Gary Ham, Rex Brooks

 

Since we had light
attendance and Gary
had to leave the meeting early, we focused on exploring and enumerating all the
potential options for item #15 on the Issues List.

 

Item #15 is the requirement
to allow multiple representations of a Target Area (for example both Polygon
and LocCode) and to be able to specify precedence (an ordering) which indicates
which representation is most accurate.

 

Ways to do this include:

1) Specify that the
precedence be the “document order” in the XML text. – We would
have to redefine the schema to remove the current sequence order restriction -
[Gary] expressed
concern that certain parsers reply on sequence order for efficiency (i.e SAX vs
DOM parsers)

 

2) Use an attribute directly
in the tags (i.e. <polygon precedence=”true”> - This would require
parsing all elements to find which are set to “true” which could
confusingly be set twice or more.

 

3) Use an attribute in
<target area> (i.e. <targetArea most_accurate=”polygon”>
- This would at least always be in same place and if it where not present, or ignored,
it would match today’s behavior.

 

4) Add a <MostAccurate>
tag: ie:

 

      <TargetArea>

            <Polygon>

                  <MostAccurate>

                  ...

            </Polygon>

            <Circle>

                  ...

            </Circle>

      </TargetArea>

      

 

      

5) Add explicit
<primary> and <secondary> container elements

 

      <TargetArea>

            <PrimaryRepresentation>

<Polygon>

                  ...

                  </Polygon>

            </PrimaryRepresentation>

            <SecondaryRepresentation>

                  <Circle>

                  ...

                  </Circle>

<SecondaryRepresentation>           

      </TargetArea>

            

 

 

6) Specify a set universal order
of accuracy: i.e. <Polygon> is always the best representation, then
<LocCode>, then <Circle>, then <BoundingBox>, etc.

 

      [Hans]
expressed problems with any universal ordering because there are clear cases
where the order would be different. For example when the target area is a state
then the locCode is exact and the polygon is an approximation. When the target
area is a plume, then the polygon is a best estimate and the locCodes are a
poor approximation.

 

 

Additional discussion
points:

[Gary] Expressed a need to continue to support
unions of multiple target areas.

[Gary] Thought that unions of different
representation types should be supported, i.e. the target area is a
<LocCode> plus a <Polygon>. 

 

 

 

-- 

Hans Jespersen

Principal Systems Engineer

Solace Systems Inc.

2051 Landings Drive, Mountain View, CA 94043

Phone: (650)
924-2670



http://www.solacesystems.com