ISO
ISO TC 211 Geographic information/Geomatics Committee site

XML schema representations of geographic technology standards

Geospatial EXtent (GEX)

Geospatial EXtent (GEX) Version: 1.3

UML diagram of Geographic Extent classes in the gex namespace
Figure 1. Classes in the gex namespace

GEX 1.3 is an XML Schema implementation derived from ISO 19115-1, Geographic Information - Metadata - Part 1: Fundamentals, Clause 6.6.1. It includes elements for specifying geospatial properties of a resource, including extent and spatial reference systems. The XML schema was encoded using the rules described in ISO/TS 19139:2007.

XML Namespace for gex 1.3

The namespace URI for gex 1.3 is https://schemas.isotc211.org/19115/-1/gex/1.3.

XML Schema for gex 1.3

gex.xsd is the XML Schema document to be referenced by XML documents containing XML elements in the gex 1.3 namespace or by XML Schema documents importing the gex 1.3 namespace. This XML schema includes (indirectly) all the implemented concepts of the gex namespace, but it does not contain the declaration of any types.

extent.xsd implements the UML conceptual schema defined in ISO 19115-1, Geographic Information - Metadata - Part 1: Fundamentals, Clause 6.6.1. It was created using the encoding rules defined in ISO 19118, ISO 19139.

https://schemas.isotc211.org/19115/-1/gex/1.3.0/extent.xsd contains the following classes:

  • EX_Extent

  • AbstractEX_GeographicExtent

  • EX_BoundingPolygon

  • EX_GeographicBoundingBox

  • EX_GeographicDescription

  • EX_TemporalExtent

  • EX_SpatialTemporalExtent

  • EX_VerticalExtent

The gex 1.3 namespace imports these other namespaces:

Name Standard Prefix Namespace Location Schema Location

Geographic Common Objects

gco

https://schemas.isotc211.org/19103/-/gco/1.2.0

gco.xsd

Geographic Markup Wrappers

gmw

https://schemas.isotc211.org/19163/-/gmw/1.1.0

gmw.xsd

Metadata Common Classes

mcc

https://schemas.isotc211.org/19115/-1/mcc/1.3.0

mcc.xsd

Geospatial Meta-Language

gml

http://schemas.opengis.net/gml/3.2.1/gml.xsd

http://schemas.opengis.net/gml/3.2.1/gml.xsd

Referencing By Coordinates

rbc

https://schemas.isotc211.org/19111/-/rbc/3.0.1

rbc.xsd

Schematron Validation Rules for mdb 1.3

Schematron rules for validating instance documents required for a complete validation are:

Package name File name Location Constraint tested

Geographic EXtent

gex.sch

https://schemas.isotc211.org/19115/-1/gex/1.3.0/gex.sch

  • EX_Extent - count (description + geographicElement + temporalElement + verticalElement) \>0

Schematron Validation Rules for gex 1.3

Schematron rules for validating instance documents of the gex 1.3 namespace are in gex.sch.

Working Versions

When revisions to these schema become necessary, they will be managed in the ISO TC211 Git Repository.