Location Object and GML Issues H. Tschofenig C. Guenther.
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Location Object and GML Issues H. Tschofenig C. Guenther
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Transcript of Location Object and GML Issues H. Tschofenig C. Guenther.
Location Object and GML Issues
H. TschofenigC. Guenther
Use of GML in Geopriv
GML consists of a set of XML schemas (http://schemas.opengis.net/gml/) and the proper GML specification (http://www.opengis.org/docs/02-023r4.pdf).
GML = Geography Markup Language
Series of XML schemas for describing geographic data, http://schemas.opengis.net/gml/.
Current version: 3.0: http://www.opengis.org/docs/02-023r4.pdf. (there are 3.0.1 versions of the GML schemas).
Developed by: OpenGIS Consortium (OGC), http://www.opengis.org, industry consortium consisting of 258 companies, government agencies and universities.
What does it mean to use GML?
feature.xsd
temporal.xsd
geometryBasic2d.xsd
geometryBasic0d1d.xsd
measure.xsd
units.xsd
dictionary.xsd gmlBase.xsd
basicTypes.xsd xLinks.xsd
Problem
Some additional details on the usage of GML for Geopriv is required.
For Geopriv we do not need many of the feature.xsd elements. GML v3 does not include Civil Location.
Approach 1: Generate a GML application
A GML application schema is an XML schema that uses the type and element definitions of a GML profile as a basis and includes or extends them in new type and element definitions. (see Chapter 8)
Similar to the approach currently taken (i.e., import feature.xsd).
Following the guidance provided by GML allows better alignment with Geopriv.
Approach 2: Generate a GML profile
A GML profile consists of XML schemas that are defined in such a way that XML instance documents valid against the profile schemas are also valid against the full set of GML schemas (chapter 7.16).
A GML profile defines XML types and elements that are consistent with the complete GML set of schemas, but potentially restricts the complete GML vocabulary and syntax.
Geopriv could define a GML profile suitable for its needs.
Conclusions and Next Steps
No doubts: GML is certainly powerful and suitable for Geopriv.
Constraints: Work on Location Object needs to be finished soon.
Goal: — We need to describe in more detail what it means to say "Use
GML feature.xsd."— Implementation experience will provide additional insights.
