Optional Parameters SPS tasking parameters representation
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Listing 3 – example for optional and required tasking parameters
swe:DataRecord …
-- Mandatory Parameter--
swe:field name
= taskTimeFrame
swe:TimeRange
optional =
false
… -- … --
swe:TimeRange swe:field
-- Optional Parameter--
swe:field name
= p
ositioningChoice swe:DataChoice
optional =
true
…
swe:item name
= pointToLookAt
swe:Vector …
-- … -- swe:Vector
swe:item swe:item
name =
relativePositioning swe:DataRecord
…
-- Optional Parameter--
swe:field name
= alPan
relativeHorizont swe:Quantity
optional =
true
… -- … --
swe:Quantity swe:field
-- Optional Parameter--
swe:field name
= Pan
relativeVertical swe:Quantity
optional =
true
… -- …--
swe:Quantity swe:field
swe:DataRecord swe:item
swe:DataChoice swe:field
-- Optional Parameter--
swe:field name
= focalLength
swe:Quantity
optional =
true
… -- …--
swe:Quantity swe:field
swe:DataRecord
7.4.2 Default Values
All data components defined in [OGC 08-094] can be either used as data descriptors or data containers. Data containers set the attribute values, data descriptors don’t. SPS uses
both descriptors and containers to describe tasking parameters Given values indicate default values. The SPS can set default values for each tasking parameter. An SPS may
but is not required to provide default values. The client can either accept this default value and use it as-is or overwrite it in a tasking request.
130 Copyright © 2011 Open Geospatial Consortium
Listing 4 – example of a tasking parameter description without default values
swe:DataRecord …
-- -- swe:field
name =
positioningChoice swe:DataChoice
… swe:item
name =
pointToLookAt swe:Vector
… -- --
swe:coordinate name
= h
swe:Quantity definition
= http:sweet.jpl.nasa.gov2.0spaceCoordinates.owlVertical
axisID =
h swe:uom
code =
m swe:Quantity
swe:coordinate swe:Vector
swe:item -- --
swe:DataChoice swe:field
-- -- swe:DataRecord
Listing 5 – example of a tasking parameter description including default values
swe:DataRecord …
-- -- swe:field
name =
positioningChoice swe:DataChoice
… swe:item
name =
pointToLookAt swe:Vector
… -- --
swe:coordinate name
= h
swe:Quantity …
swe:uom code
= m
swe:value swe:value
swe:Quantity swe:coordinate
swe:Vector swe:item
-- -- swe:DataChoice
swe:field -- --
swe:DataRecord
If an SPS uses a DataArray or Matrix in its tasking parameters description then it may provide default values that are encoded according to a description that the service also
provides in that arraymatrix. As clients may safely ignore given default values, they can also ignore unknownunsupported encodings that they might encounter in a
DataArrayMatrix provided by an SPS.
7.4.3 Updatable parameters
AbstractDataComponents as defined in OGC 08-094 clause 7.2 provide an optional
updatable attribute. This attribute is set to true if the corresponding tasking parameter can
be included in an Update request. If the attribute is not set or set to false, the tasking parameter cannot be updated and thus no value for it is included in an Update request.
Clients can simply strip any component from the tasking parameter description retrieved via DescribeTasking that are not updatable. The resulting description defines the structure
Copyright © 2011 Open Geospatial Consortium 131
of the parameters to be included in an update request. If the data component that represents the whole tasking parameter descriptor for tasking a given procedure is not
updatable then the Update operation is not realized for that procedure.
Listing 6 – example of tasking parameter description with updatable and non-updatable parameters
-- Update operation is implemented for procedure -- swe:DataRecord
… -- Parameter not updatable --
swe:field name
= taskTimeFrame
swe:TimeRange … updatable
= false
-- -- swe:TimeRange
swe:field -- Parameter is updatable --
swe:field name
= positioningChoice
swe:DataChoice …
-- Choice item is available for Update -- swe:item
name =
pointToLookAt swe:Vector
… -- --
swe:Vector swe:item
-- Choice item is available for Update -- swe:item
name =
relativePositioning swe:DataRecord
… -- Record field is available for Update --
swe:field name
= relativeHorizontalPan
swe:Quantity …
-- -- swe:Quantity
swe:field -- Record field is available for Update --
swe:field name
= relativeVerticalPan
swe:Quantity …
-- -- swe:Quantity
swe:field swe:DataRecord
swe:item swe:DataChoice
swe:field -- Parameter is updatable --
swe:field name
= focalLength
swe:Quantity …
-- -- swe:Quantity
swe:field swe:DataRecord
Removing all components that are not updatable would result in the following parameter description. A client would use this description in an Update request.
132 Copyright © 2011 Open Geospatial Consortium
Listing 7 – example of tasking parameter description for update request where all non-updatable parameters have been removed
swe:DataRecord …
swe:field name
= positioningChoice
swe:DataChoice …
swe:item name
= pointToLookAt
swe:Vector …
-- -- swe:Vector
swe:item swe:item
name =
relativePositioning swe:DataRecord
… swe:field
name =
relativeHorizontalPan swe:Quantity
… -- --
swe:Quantity swe:field
swe:field name
= relativeVerticalPan
swe:Quantity …
-- -- swe:Quantity
swe:field swe:DataRecord
swe:item swe:DataChoice
swe:field swe:field
name =
focalLength swe:Quantity
… -- --
swe:Quantity swe:field
swe:DataRecord
7.4.4 Constraintsrestrictions
Most of the simple components defined in SWE Common allow provision of constraint attributes. Those can be set by SPS to constrain allowed values for tasking parameters.
Listing 8 – example of constraintsrestrictions on tasking parameter values
swe:DataRecord …
swe:field name
= taskTimeFrame
-- -- swe:field
swe:field name
= positioningChoice
swe:DataChoice optional
= true
swe:item name
= pointToLookAt
-- -- swe:item
swe:item name
= relativePositioning
swe:DataRecord …
swe:field name
= relativeHorizontalPan
swe:Quantity …
swe:uom code
= deg
swe:constraint swe:AllowedValues
swe:interval -180 180
swe:interval swe:AllowedValues
swe:constraint
swe:Quantity swe:field
swe:field name
= relativeVerticalPan
swe:Quantity …
swe:uom code
= deg
swe:constraint swe:AllowedValues
swe:interval -90 90
swe:interval
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swe:AllowedValues swe:constraint
swe:Quantity swe:field
swe:DataRecord swe:item
swe:DataChoice swe:field
swe:field name
= focalLength
swe:Quantity …
swe:uom code
= mm
swe:constraint swe:AllowedValues
swe:interval 3.5 10
swe:interval swe:AllowedValues
swe:constraint
swe:Quantity swe:field
swe:DataRecord