QuantityRange Element Requirements Class: Basic Types and Simple Components Schemas Requirements Class

SWE Common Data Model OGC 08-094r1 The pair of values can be omitted like with any other data component in the case where it is provided in a separate data stream.

8.1.12 TimeRange Element

The “TimeRange” element is the XML schema implementation of the “TimeRange” UML class defined in clause 7.2.14. The schema snippet for this element and its corresponding complex type is shown below: element name = TimeRange substitutionGroup = swe:AbstractSimpleComponent type = swe:TimeRangeType complexType name = TimeRangeType complexContent extension base = swe:AbstractSimpleComponentType sequence element name = uom type = swe:UnitReference element name = constraint maxOccurs = 1 minOccurs = type = swe:AllowedTimesPropertyType element name = value maxOccurs = 1 minOccurs = type = swe:TimePair sequence attribute name = referenceTime type = dateTime use = optional attribute name = localFrame type = anyURI use = optional extension complexContent complexType This element is used exactly in the same way as the “Time” element except that the “value” property takes a space separated pair of time positions. The next example shows how to express a time period with such a component: swe:TimeRange definition = http:www.opengis.netdefpropertyEO0SurveyPeriod swe:label Survey Period swe:label swe:uom xlink:href = http:www.opengis.netdefuomISO-86010Gregorian swe:value 2008-01-05T11:02:54Z 2009-11-05T16:29:26Z swe:value swe:TimeRange The pair of time positions can be omitted like with any other data component in the case where it is provided in a separate data stream.

8.1.13 Quality Element Group

The “Quality” group is the XML schema implementation of the “Quality” Union UML classifier defined in clause 7.2.15. The schema snippet for this XML schema group is shown below: group name = Quality choice element ref = swe:Quantity element ref = swe:QuantityRange element ref = swe:Category element ref = swe:Text choice group Copyright © 2011 Open Geospatial Consortium 81 OGC 08-094r1 SWE Common Data Model This group allows the use of some of the XML elements define above to add qualitative information to a simple data component. The following examples illustrate how this is done in a SWE Common XML instance. This first example shows that quality is expressed by wrapping the value in one of the data components defined previously that is appropriate for the desired representation. Here a “Quantity” element is used to specify a decimal value representing relative accuracy: swe:Quantity definition = http:sweet.jpl.nasa.gov2.0sciUncertainty.owlAccuracy swe:label Relative Accuracy swe:label swe:uom code = swe:value 5 swe:value swe:Quantity This snippet is then inserted within the data component element whose value’s quality needs to be expressed. This is shown below: swe:Quantity definition = http:sweet.jpl.nasa.gov2.0physDynamics.owlVelocity swe:label Velocity swe:label swe:description Linear velocity of the vehicle swe:description swe:quality swe:Quantity definition = http:sweet.jpl.nasa.gov2.0sciUncertainty.owlAccuracy swe:label Relative Accuracy swe:label swe:uom code = swe:value 5 swe:value swe:Quantity swe:quality swe:uom code = ms swe:value 23.5 swe:value swe:Quantity This example is a velocity measurement of 23.5 meters per seconds, with a relative accuracy of 5. Absolute accuracy could have been specified as well by using a different definition URI and setting the unit of the accuracy value to “ms”. Bidirectional tolerance is a measure of quality that is often used for specification of mechanical parts. Such a use case is shown below: swe:Quantity definition = http:sweet.jpl.nasa.gov2.0spaceExtent.owlThickness swe:label Thickness swe:label swe:description Thickness measured by the sheet metal gauge swe:description swe:quality swe:QuantityRange definition = http:sweet.jpl.nasa.gov2.0sciUncertainty.owlTolerance swe:label Dimensional Tolerance swe:label swe:uom code = um swe:value -20 +0 swe:value swe:QuantityRange swe:quality swe:uom code = mm swe:value 5.6 swe:value swe:Quantity In the previous example, the sheet of metal is measured to have a thickness between 5.58 and 5.6 millimeters. Note that a different unit i.e. micrometer is used for the tolerance value. 82 Copyright © 2011 Open Geospatial Consortium