This section describes how OS MasterMap Highways Network is defined in GML. An understanding of XML (Extensible Mark-up Language) and XML schema is required.
GML is an XML grammar for expressing geographic features. GML serves as a modelling language for geographic systems as well as an open interchange format for geographic transactions on the Internet.
XML schemas are used to define and validate the format and content of GML. The GML 3.2 specification provides a set of schemas that define the GML feature constructs and geometric types. These are designed to be used as a basis for building application-specific schemas, which define the data content.
The Path Network uses the following application schemas; LinearHighwayNetwork.xsd, HighwaysWaterTransportNetwork.xsd, RoutingAndAssetManagement.xsd and OSProducts.xsd which are referenced by the data.
The LinearHighwaysNetwork.xsd defines the features which make up the Path Network. Therefore, it imports the INSPIRE transport network road application schema.
The HighwaysWaterTransportNetwork.xsd defines the features which make up the Ferry Network. Therefore, it imports the INSPIRE transport network water application schema.
The OSProducts.xsd defines the feature collection and feature members. In addition, this application schema will define the transactions used for a Change Only Update supply.
The application schema uses the following XML namespaces, for which definitions are available here: