|| Model: Conceptual, Logical, XML
|| Logical, XML
|| Using Constituent as Feature-of-Interest
|| B. Brodaric
|| Logical, XML
|| Linkage between GWML2 and TimeSeriesML
|| B. Simons
|| Change documentation to state that we used GML 3.3
|| E. Boisvert
1. Using Constituent as Feature-of-Interest
OM_Observation featureOfInterest can be the samplingFeature (GW_Well) or the sampledFeature (GW_Aquifer). For some observed properties (e.g. pH) the former doesnt make sense, so need to be able to distinguish the two. The featureOfInterest for the observations was mapped to the GW_Well (i.e. the samplingFeature), but it should be the ultimate featureOfInterest (e.g. the GW_FluidBody.
The Observations & Measurements specification proposes two patterns for featureOfInterest:
(1) the feature of interest can either refer to the real world object that is being observed, or
(2) to a sampling feature (SF_SamplingFeature) that acts as a proxy for the real world feature (which is then accessible through the sampling features sampledFeature property).
Because the property featureOfInterest has cardinaliy 1..1, a data provider must choose one of these approaches. Problems occur when a sampling feature is chosen: while many observations can refer to the same domain feature, it is impossible to navigate back to the sampling feature. Solutions have been proposed using OM_Process to document the relationship between the observation and the sampling feature, but they are cumbersome and require much encoding. Consequently, the JSON (OGC 15-100) and RDF encodings for O&M include an extra samplingRegime property that is absent from the GML encoding. In GWML2, there is no restriction on featureOfInterestit can refer to a real world feature or a sampling feature.
Put in change request to OGC to modify O&M conceptual model and OMXML to have ultimate featureOfInterest (0..n) and samplingStrategy (0..n) for intermediate sampling features.
2. Linkage between GWML2 and TimeSeriesML
For GW_Flow, gwFlowVolumeRate is OM_Measurement: that constrains the result to be a gml:Measurement , so a single value with a uom but these may be ranges.
Additionally, the use of OM_Measurement precludes using TimeSeries
as a result (uses a specialisation of OM_Observation). The GWML2IE
did not investigate whether there were any properties that have data type OM_Measurement that could be a time series.
Investigate whether there are any properties that require data type to be OM_Observation.
- 08 Oct 2015
- 12 Aug 2015
3. GML 3.3 encoding
The encoding rule we used (we might want to check if it's all true) is actually GML 3.3 - specially the CodeType
-> gml:ReferenceType. I always thought it was a INSPIRE thing, it's not. We must change the documentation and state that we used GML 3.3 (GML 3.3 is not a new schema, it's actually an extension of 3.2 + encoding patterns)
- 02 Nov 2015
- All optional properties - consistent with GWML2.0
- On OGC standardization process
- schema will change
- instance will change
- service will change