Modifications to DescribeCoverage OGC® Web Coverage Service Interface Standard - CRS ExtensionWCS-CRS-extension
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Copyright © 2014 Open Geospatial Consortium.
6.4 Modifications to GetCoverage 6.4.1 Modifications to the GetCoverage request
The GetCoverage request is extended with two optional parameters indicating the CRSs for subsetting coordinates and for the result coverage. If these parameters are omitted then all
access will be performed in the coverage’s Native CRS as reported in its Coverage Description.
Note This normally ensures that the coverage’s unchanged range set values are retrieved, assuming
that no other operations than subsetting is performed in the GetCoverage request.
Requirement 6 crsgetCoverage-crs: A GetCoverage request shall adhere to Figure 2, Table 4, and the XML schema defined for
this CRS Extension whereby, in the XML request encoding, the GetCoverage
wcs:Exten- sion
element shall contain exactly one
GetCoverageCrs
element.
Figure 2 —
GetCoverage
UML diagram with
GetCoverageCRS
extension Table 4 — Components of
CRS::GetCoverageCrs
structure
Name Definition
Data type Multiplicity
subsettingCrs
CRS Identifier indicating the CRS in which the request subsetting
coordinates are expressed
anyURI
zero or one optional
outputCrs
CRS Identifier indicating the CRS of the result coverage
anyURI
zero or one optional
A GetCoverage request may contain an additional parameter,
subsettingCrs
, to indicate the CRS in which the subsetting coordinates passed are expressed. Admissible values for this
parameter are URIs which resolve to exactly one CRS.
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Copyright © 2014 Open Geospatial Consortium.
Requirement 7 crsgetCoverage-subsettingCrs-default: If the
subsettingCrs
parameter is not present in a GetCoverage request then the request
shall be evaluated as if a
subsettingCrs
parameter equal to the coverage’s Native CRS as provided in the Coverage Description had been provided.
Requirement 8 crsgetCoverage-subsettingCrs-uniqueCrsName: The
subsettingCrs
parameter in a GetCoverage request, if present, shall have as its value
a CRS Identifier.
Requirement 9 crsgetCoverage-subsettingCrs-availableCrs: The
subsettingCrs
parameter in a GetCoverage request, if present, shall have as its value
a CRS Identifier described in the
crsSupported
list delivered in the
CrsMetadata
element of the Capabilities document of the server addressed.
Note As per WCS Core [OGC 09-110r3] every coverage has a Native CRS associated which will be
contained in this list among potentially more CRSs; therefore, this list will never be empty as long as the server offers at least one coverage.
A GetCoverage request may contain an additional parameter,
outputCrs
, to indicate a particular CRS in which the client wants to receive the result coverage produced by the
server. Admissible values for this parameter are URIs which resolve to exactly one CRS.
Requirement 10 crsgetCoverage-outputCrs-default: If the
outputCrs
parameter is not present in a GetCoverage request then the request shall
be evaluated as if an
outputCrs
parameter equal to the
subsettingCrs
parameter value assumed for this request’s evaluation had been provided.
Requirement 11 crsgetCoverage-outputCrs-uniqueCrsName: The
outputCrs
parameter in a GetCoverage request, if present, shall have as its value a
CRS Identifier.
Requirement 12 crsgetCoverage-outputCrs-availableCrs: The
outputCrs
parameter in a GetCoverage request, if present, shall have as its value a
CRS Identifier described in the
crsSupported
list delivered in the
CrsMetadata
element of the Capabilities document of the server addressed.
Note As per WCS Core [OGC 09-110r3] every coverage has a Native CRS associated which will be
in this list among potentially more CRSs; therefore, this list will never be empty as long as the server offers at least one coverage.