GML and Symbol Discussions

[bschroeder@esri.com]

Hi all,

Just a quick set of comments on 2 issues we have been discusssing recently.  Symbols and the GML/CAP message. 

1) GML 
The proposal distriubted by Elliot last week has set a GML 3 profile, the CAP schema would be an application schema based on that, it would  extend those generic types to the CAP features. 

However such an approach doesn't guarantee wide availability with WFS and GML implementations. 
 
The schema/proposal introduced on May 13th, located at: 

http://www.oasis-open.org/apps/org/workgroup/emergency-gis/download.php/1999/2003-05-13_gml4ems_00003.000.xsd

, defines a geometry that can be used as part of the CAP alerts, based on the GML 3 schema. 

This (gml4ems.xsd) can be extended to a simplified feature model that can be utilized in WFS. 

There are other initiatives inside OGC like OpenLS that set presedence for this. There's also another initiative that's going on at the moment as part of pilot CIPI 1. 2, through which a profile of GML that is used by all WFS vendors to interoperate can be utilized. That profile has a simple feature representation. 

These simplifed and lighter weight approaches may offer a better solution for this effort and meet the requirements for: Wide availability, extensibility and interoperability.

2) Symbols
What is our goal and/or requirement vis a vis emergency management symbols? 

Is the goal to adopt and/or develop a standard symbol set?

To then take the adopted set and develop a  specification on how to employ it?

This leads us to the question is it WMS or WFS we are looking at as the deployment mechanism for symbols?