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

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