The /UnitsOfMeasure package provides an additional set of 'unit of measure' classes to supplement those provided in ISO 19103 Basic types [1] (e.g. the class of units for measurement of temperature is not included in ISO 19103, so it is added to METCE as UomTemperature. Specific units of measure instances of these classes (e.g. "Celsius" is an instance of UomTemperature).<br /></p><p><br /></p><p>All 'unit of measure' classes are defined as specialisations of UnitOfMeasure (from ISO 19103 Basic types).<br /></p><p><br /></p><p>This package shall not be implemented as XML schema as instances of gml:MeasureType reference unit of measure using gml:UomIdentifier rather than referencing any specific UnitOfMeasure object directly.<br /></p><p><br /></p><p>[<font color="#ff0000">Looking at the GML implementation of ISO 19103, these unit of measure classes are not implemented as XML types ... instead gml:MeasureType provides attribute 'uom' of Type 'UomIdentifier' to enable a unit of measure to be referenced. Best practice indicates that one should use the scheme from unitsofmeasure.org (with the URIs for these units published via the OGC namespace) to refer to units of measure</font>]<br /></p><p><br /></p><p>[1] ISO 19103 Basic Types only provides a very limited palette of units<br /></p>