32 Copyright © 2012 Open Geospatial Consortium
The element gmllr:startValue specifies the measure value at the start of the gmllr:LinearElement for each appropriate Linear Referencing Method. If not provided, a default value of 0 zero is assumed for all
Linear Referencing Methods.
9.3.6 LinearElementPropertyType
complexType name=LinearElementPropertyType sequence minOccurs=0
element ref=gmllr:LinearElement sequence
attributeGroup ref=gml:AssociationAttributeGroup complexType
A property that has a linear element as its value domain may either be an appropriate linear element encapsulated in an element of this type or an XLink reference to a remote linear element where remote
includes linear elements located elsewhere in the same document. Either the reference or the contained element shall be given, but neither both nor none.
9.3.7 StartValueType
complexType name=StartValueType simpleContent
extension base=double attribute name=uom type=gml:UomIdentifier
attribute name=lrm type=anyURI use=required annotation
appinfo gml:targetElement
gmllr:LinearReferencingMethod gml:targetElement
appinfo annotation
attribute extension
simpleContent complexType
Because the start value is a function of the Linear Referencing Method, the gmllr:StartValueType extends a start value of type double with two attributes.
The optional attribute gmllr:uom provides the units of measure for the start value. If none is provided, the uom value defaults to the units value of the Linear Referencing Method.
The mandatory attribute gmllr:lrm specifies the Linear Referencing Method for which this start value applies. Though the type is anyURI, it is expected that the value will be a reference to an already defined
gmllr:LinearReferencingMethod object.
9.3.8 LinearReferencingMethod
complexType name=LinearReferencingMethodType complexContent
extension base=gml:AbstractGMLType sequence
element name=name type=gmllr:LRMNameType element name=type type=gmllr:LRMTypeType
element name=units type=gml:UomIdentifier element name=constraint type=string minOccurs=0
Copyright © 2012 Open Geospatial Consortium 33
sequence extension
complexContent complexType
element name=LinearReferencingMethod type=gmllr:LinearReferencingMethodType substitutionGroup=gml:AbstractGML
gmllr:LinearReferencingMethod implements ISO 19148 LR_LinearReferencingMethod see ISODIS 19148, 6.2.10.
A gmllr:LinearReferencingMethod specifies the manner in which measurements are made along a linear element.
The element gmllr:name specifies the name of the Linear Referencing Method, such as kilometre-point. Allowable values are specified by the gmllr:LRMNameType codelist.
The element gmllr:type specifies the type of Linear Referencing Method. Allowable values are specified by the gmllr:LRMTypeType codelist.
The element gmllr:units specifies the units of measure used by the Linear Referencing Method as a gml:UomIdentifier. This applies to measurements made along the linear element.
The optional element gmllr:constraint allows for optional string values which specify any constraints imposed by the Linear Referencing Method.
9.3.9 LinearReferencingMethodPropertyType
