1. Modelling approaches for EO application schema
HMA-FO meeting, Darmstadt
29 September, 2009
Andrew Woolf

2. conceptual modelling “interoperability” “conceptual modelling”
the ability of two parties to undertake a meaningful exchange of information
“conceptual modelling”
the formalism adopted by ISO TC211 for interoperability of geospatial data

3. conceptual modelling some principles:
the 100% principle: all relevant aspects of a universe of discourse shall be described in the conceptual schema (i.e. a universe of discourse is defined by its conceptual schema)
the conceptualisation principle: a conceptual schema shall contain only aspects that are relevant to a universe of discourse (e.g. it should be independent of physical or technological implementation details)*
* because the “lifetime of a technical implementation is shorter than the lifetime of the information it handles” (CEN/TR 15449)
the Helsinki principle: any meaningful exchange should be based on agreed syntactic and semantic rules, with which a conceptual schema should be formulated and interpreted

4. in practice conceptual modelling...
“...is the process of creating an abstract description of some portion of the real world and/or a set of related concepts.” (ISO 19101)
Feature types
ISO 19103/9
Universe of discourse
Application schema
ISO 19136
<gml:definitionMember>
<gml:description>The taxon name</gml:description>
<om:Phenomenon gml:id="taxon">
</NDGPhenomenonDefinitions>
</gml:definitionMember>
</om:Phenomenon>
<gml:name codeSpace="
<!--===================================================================-->
<gml:featureMember>
<NDGPointFeature gml:id="ICES_100">
<!-- ============================================================== -->
<gml:FeatureCollection>
<NDGPointDomain>
<location> </location>
<NDGPosition srsName="urn:EPSG:geographicCRS:4979" axisLabels="Lat Long" uomLabels="degree degree">
<domainReference>
</domainReference>
</NDGPosition>
<gml:rangeParameters>
<gml:DataBlock>
<gml:rangeSet>
</NDGPointDomain>
<gml:CompositeValue>
<gml:measure uom="#amount"/>
<gml:measure uom="#tn"/>
<gml:valueComponents>
</gml:valueComponents>
<gml:measure uom="#gsm"/>
'ANTHOZOA',63.1,missing
<gml:tupleList>
</gml:rangeParameters>
</gml:CompositeValue>
'Scoloplos armiger',66.1,missing
'Pholoe',10,missing
'Capitellidae',131.8,missing
'Spiophanes bombyx',60.3,missing
'Spio filicornis',10,missing
'Hypereteone lactea',6.8,missing
'Owenia fusiformis',23.4,missing
'Anaitides mucosa',6.8,missing
'Anaitides groenlandica',13.2,missing
ISO 19118
ISO 19110

5. the ‘model-driven approach’
(implied by the Helsinki principle)
<?xml version="1.0" encoding="UTF-8"?> <ModelCode> <name>MyAGCM</name> <language>FORTRAN</language> <version>2</version> <author>AWoolf</author> <author>ANOther</author> <deployedOn> <Computer> <location>HPCx Daresbury</location> <os>AIX</os> <peakPower>15.3TFlops</peakPower> <numProcessors>2560</numProcessors> </Computer> </deployedOn> </ModelCode>

6. tooling UML modelling UML → XML Schema Enterprise Architect
low cost
XMI export
ISO HMMG
UML → XML Schema
ShapeChange
FullMoon

7. e.g. INSPIRE
<complexType abstract="true" name="SurfaceWaterType"> <complexContent> <extension base="gml:AbstractFeatureType"> <sequence> <element maxOccurs="unbounded" minOccurs="0" name="geographicalName" nillable="true">
...
</sequence> </extension> </complexContent> </complexType>
<complexType name="StandingWaterType"> <complexContent> <extension base="hy-p:SurfaceWaterType"> <sequence> <element name="elevation" nillable="true"> ...
</element> <element name="meanDepth" nillable="true"> ...
</element> <element name="surfaceArea" nillable="true"> <complexType> <simpleContent> <extension base="gml:AreaType"> <attribute name="nilReason" type="gml:NilReasonType"/> </extension> </simpleContent> </complexType> </element> </sequence> </extension> </complexContent> </complexType>

8. 06-080r4 ‘reverse-engineered’

9. issues – modelling GML CR 08-114: deprecate gml:Observation
use ISO O&M...
GML 3.2.1: gml:metaDataProperty deprecated
add explicit metadata property...
Schema issues resulting from non-MDA
use MDA...

10. issues – product Specific limb-sounding issues
see presentation Victoria Bennett
observed/geophysical parameters
Observation.observedProperty
limb-sounding geometry
quality flagging in vertical
target processing level

11. coverage result?
ISO ‘Observations and Measurements’

12. use of WFS... For EO metadata? For EO ‘result’?
Use of GML xlink with coverage data
Boston TC
INSPIRE encoding rule
Annex C
“Use of xlink in GML – Profile for file-based data content” (a bit out of date)
WFS demo at Valencia TC

17. GML xlink <someGMLElement xlink:arcrole="localXpath"
where content is to be inserted
<someGMLElement
xlink:arcrole="localXpath"
xlink:href="storageDescriptor#portion"
xlink:role="storageSchemaIdentifier"
xlink:show="embed"
xlink:actuate="onRequest | onLoad"/>
the remote content
remote resource (exchange format) type

18. GML xlink Example: (similar for lat, lon axes)
<gml:rangeSet> <gml:ValueArray> <gml:valueComponent> <gml:QuantityList uom="degrees_celsius"> </gml:QuantityList> </gml:valueComponent> </gml:ValueArray> </gml:rangeSet>
(similar for lat, lon axes)
<gml:rangeSet> <gml:ValueArray> <gml:valueComponent xlink:href="myfile.nc#tempvbl" xlink:arcrole="QuantityList" xlink:role="urn:mimetype:application/x-netcdf"> <gml:QuantityList uom="degrees_celsius"/> </gml:valueComponent> </gml:ValueArray> </gml:rangeSet>

19. Summary MDA ISO 19136 / GML 3.2 ISO 19156 / O&M (observedProperty)
06-080r4 minor issues (non-MDA)
specific issues for limb-sounding
coverage result
WFS (for result and/or EO application schema)