Copyright © 2010 Open Geospatial Consortium, Inc.
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[…] eop
:EarthObservationEquipment gml
:using […]
opt : EarthObservation
6.3.2.2 Mission specific extended namespace
Mission specific extended namespace phr for example contains : - phr words;
- a phr:EarthObservation element that inherits from opt:EarthObservation. This inheritance is an XML schema extension to avoid restriction problems with no
element added because all elements fit inside one of the Observation property metadaProperty, validTime, using, target or resultOf;
- one or more extension of existing opt properties e.g. in phr, an extension of opt:EarthObservationResult to add cloudCoverPercentageConfidenceIndex.
These rules are closed to those described in the thematic extended namespace. However, the property extension approach leads to a drawback in the mission specific case.
Indeed, from a client point of view, an “eop” enabled reader must encounter well-known structures under a “eop” properties. This may not be a problem for “eop” and thematics
schemas since they are completely described in this document i.e. structure can be “hard coded”.
However, a mission specific schema shall follow the rules described in this document but the content of this schema is not in the scope of this document. Thus a generic “eop”
enabled reader shall be able to process complex schema inheritance mechanisms to “understand” mission specific data.
To avoid this drawback, we introduce an attribute eop:type at the eop level. This attribute is required for properties that extends one of eop or thematic property. This
attribute is expected to contain the name of the property it extends directly. This mechanism is comparable to the ISO19139 gco:isoType.
For example for a phr:DataStrip that extends opt:EarthObservation :
phr :DataStrip
eop:type=opt:EarthObservation [...]
gml :resultOf
phr :EarthObservationResult
eop:type=opt:EarthObservationResult eop
:browse eop
:product eop
:mask opt
:cloudCoverPercentage uom=30 opt
:cloudCoverPercentage phr
:cloudCoverAssessmentConfidence uom=10 phr
:cloudCoverAssessmentConfidence phr
:EarthObservationResult gml
:resultOf [...]
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