Copyright © 2012-2014 Open Geospatial Consortium 72
10 XML Implementation normative
This standard defines a GML XML Schema implementation that is compliant to the UML conceptual models defined in Section 9. Preliminary XML schemas were auto generated from the
models following the encoding rules Annex E of OGC Geography Markup Language v3.2 ISO 19136:2007. These were then modified to meet the requirements outlined.
Schematron patterns are also implemented for additional requirements where appropriate.
Table 9 - Mapping of WaterML2.0 UML classes to XML elements
WaterML 2.0 UML WaterML 2.0 XML
MeasurementTimeseriesTVPObservation om:OM_Observation
CategoricalTimeseriesTVPObservation om:OM_Observation
ObservationProcess wml2:ObservationProcess
MonitoringPoint wml2:MonitoringPoint
TimeseriesTVP wml2:Timeseries
MeasurementTimeseriesTVP wml2:MeasurementTimeseries
CategoricalTimeseriesTVP wml2:CategoricalTimeseries
TimeValuePair wml2:TimeValuePair
MeasurementTimeValuePair wml2:MeasurementTVP
CategoricalTimeValuePair wml2:CategoricalTVP
TimeseriesMetadata wml2:TimeseriesMetadata
MeasurementTimeseriesMetadata wml2:MeasurementTimeseriesMetadata
PointMetadata wml2:TVPMetadata
MeasurementPointMetadata wml2:TVPMeasurementMetadata
ObservationMetadata wml2:ObservationMetadata
Collection wml2:Collection
The specialisation of OM_Observation is provided through Schematron rather than a specialised XML type.
OGC WaterML 2.0 OGC 10-126r4
Table 10 - OM URIs for observation specialisations
WaterML v2.0 OGC Name
Content of om:result in WaterML2 XML
1 1
MeasurementTimeseriesTVPObservation http:www.opengis.netdefobservationTypewater
ml2.0MeasurementTimeseriesTVPObservation type=’wml2:MeasurementTimeseries
CategoricalTVPTimeseriesObservation http:www.opengis.netdefobservationTypewater
ml2.0CategoricalTVPTimeseriesObservation type=’wml2:CategoricalTimeseries’
10.1 Scope of XML implementation
The normative part of this XML implementation does not target the domain-range style of timeseries encoding. This was not included, as the schema design has not progressed through the required analysis from the Standards Working Group. The
domain-range XML encoding is provided as an informative schema, within its own namespace, allowing it to be used with the normative WaterML2.0 schema. The implementation is a conformant extension to the gmlcov schema
http:www.opengis.netgmlcov1.0 , adding support for the WaterML2.0 types. Future work will ensure the schema design is
consistent with stakeholder requirements. The major design issue relates to providing the value-level metadata that a time- value pair encoding supports. The current approach uses supplementary coverages to describe time-varying metadata such as
quality assertions. An example is provided in Annex B.
Copyright © 2012-2014 Open Geospatial Consortium 74
Table 11 - Mapping of UML to XML conformance classes
WaterML v2.0 UML Conformance Class WaterML2.0 XML Conformance Class
Timeseries Observation http:www.opengis.netspecwaterml2.0requml-timeseries-observation
confxsd-timeseries-observation
Monitoring point feature of interest http:www.opengis.netspecwaterml2.0requml-monitoring-point-feature-of-interest
confxsd-feature-of-interest-monitoring-point
Interleaved TVP style
Timeseries TVP interleaved http:www.opengis.netspecwaterml2.0requml-timeseries-tvp
confxsd-timeseries-tvp
Measurement Timeseries TVP interleaved http:www.opengis.netspecwaterml2.0requml-measurement-
timeseries-tvp
confxsd-measurement-timeseries-tvp
Categorical Timeseries TVP interleaved http:www.opengis.netspecwaterml2.0requml-categorical-timeseries-
tvp
confxsd-categorical-timeseries-tvp
Timeseries TVP interleaved Observation http:www.opengis.netspecwaterml2.0requml-timeseries-tvp-
observation
confxsd-timeseries-tvp-observation
Measurement Timeseries TVP interleaved Observation http:www.opengis.netspecwaterml2.0requml-measurement-
timeseries-tvp-observation
confxsd-measurement-timeseries-tvp-observation
Categorical Timeseries TVP interleaved Observation http:www.opengis.netspecwaterml2.0requml-categorical-timeseries-
tvp-observation
confxsd-categorical-timeseries-tvp-observation
Monitoring point exchange http:www.opengis.netspecwaterml2.0requml-monitoring-point
http:www.opengis.netspecwaterml2.0requml-sampling-feature-collections
confxsd-monitoring-point
Collection exchange http:www.opengis.netspecwaterml2.0requml-collection
confxsd-collection
Observation process exchange http:www.opengis.netspecwaterml2.0requml-observervation-process
confxsd-observation-process
