gml:AbstractGeneralTransformationType

An abstract operation on coordinates that usually includes a change of Datum. The parameters of a coordinate transformation are empirically derived from data containing the coordinates of a series of points in both coordinate reference systems. This computational process is usually "over-determined", allowing derivation of error (or accuracy) estimates for the transformation. Also, the stochastic nature of the parameters may result in multiple (different) versions of the same coordinate transformation.

This abstract complexType is expected to be extended for well-known operation methods with many Transformation instances, in Application Schemas that define operation-method-specialized value element names and contents. This transformation uses an operation method with associated parameter values. However, operation methods and parameter values are directly associated with concrete subtypes, not with this abstract type. All concrete types derived from this type shall extend this type to include a "usesMethod" element that references one "OperationMethod" element. Similarly, all concrete types derived from this type shall extend this type to include one or more elements each named "uses...Value" that each use the type of an element substitutable for the "_generalParameterValue" element. 

Complex type information

Content

• Sequence [1..1]
  1. gml:metaDataProperty [0..*]    Contains or refers to a metadata package that contains metadata properties.
  2. gml:coordinateOperationName [1..1]    The name by which this coordinate operation is identified.
  3. gml:coordinateOperationID [0..*]    An identification of a coordinate operation.
  4. gml:remarks [0..1]    Information about this object or code. Contains text or refers to external text.
  5. gml:operationVersion [1..1]    Version of the coordinate transformation (i.e., instantiation due to the stochastic nature of the parameters). Mandatory when describing a transformation, and should not be supplied for a conversion.
  6. gml:validArea [0..1]    Area or region in which this CRS object is valid.
  7. gml:scope [0..1]    Description of domain of usage, or limitations of usage, for which this CRS object is valid.
  from subst. group gml:_positionalAccuracy
  gml:_positionalAccuracyAbstract [0..*]    
  8. gml:sourceCRS [1..1]    Association to the source CRS (coordinate reference system) of this coordinate operation.
  9. gml:targetCRS [1..1]    Association to the target CRS (coordinate reference system) of this coordinate operation. For constraints on multiplicity of "sourceCRS" and "targetCRS", see UML model of Coordinate Operation package in OGC Abstract Specification topic 2.

Attributes

Used by

• Element gml:_GeneralTransformation
• Element gml:Transformation via derived type gml:TransformationType
• Element gmx:ML_Transformation via derived type gmx:ML_Transformation_Type

Type inheritance chain

• gml:AbstractGMLType
  • gml:DefinitionType
    • gml:AbstractCoordinateOperationBaseType
      • gml:AbstractCoordinateOperationType
        • gml:AbstractGeneralTransformationType
          • extended by gml:TransformationType
            • extended by gmx:ML_Transformation_Type