gml:VerticalDatumType

A textual description and/or a set of parameters identifying a particular reference level surface used as a zero-height surface, including its position with respect to the Earth for any of the height types recognized by this standard. There are several types of Vertical Datums, and each may place constraints on the Coordinate Axis with which it is combined to create a Vertical CRS. 

Complex type information

Content

• Sequence [1..1]
  from type gml:AbstractDatumBaseType
  gml:metaDataProperty [0..*]    Contains or refers to a metadata package that contains metadata properties.
  gml:datumName [1..1]    The name by which this datum is identified.
  from type gml:AbstractDatumType
  gml:datumID [0..*]    Set of alternative identifications of this datum. The first datumID, if any, is normally the primary identification code, and any others are aliases.
  gml:remarks [0..1]    Comments on this reference system, including source information.
  gml:anchorPoint [0..1]    Description, possibly including coordinates, of the point or points used to anchor the datum to the Earth. Also known as the "origin", especially for engineering and image datums. The codeSpace attribute can be used to reference a source of more detailed on this point or surface, or on a set of such descriptions. - For a geodetic datum, this point is also known as the fundamental point, which is traditionally the point where the relationship between geoid and ellipsoid is defined. In some cases, the "fundamental point" may consist of a number of points. In those cases, the parameters defining the geoid/ellipsoid relationship have been averaged for these points, and the averages adopted as the datum definition. - For an engineering datum, the anchor point may be a physical point, or it may be a point with defined coordinates in another CRS. When appropriate, the coordinates of this anchor point can be referenced in another document, such as referencing a GML feature that references or includes a point position. - For an image datum, the anchor point is usually either the centre of the image or the corner of the image. - For a temporal datum, this attribute is not defined. Instead of the anchor point, a temporal datum carries a separate time origin of type DateTime.
  gml:realizationEpoch [0..1]    The time after which this datum definition is valid. This time may be precise (e.g. 1997.0 for IRTF97) or merely a year (e.g. 1983 for NAD83). In the latter case, the epoch usually refers to the year in which a major recalculation of the geodetic control network, underlying the datum, was executed or initiated. An old datum can remain valid after a new datum is defined. Alternatively, a datum may be superseded by a later datum, in which case the realization epoch for the new datum defines the upper limit for the validity of the superseded datum.
  gml:validArea [0..1]    Area or region in which this CRS object is valid.
  gml:scope [0..1]    Description of domain of usage, or limitations of usage, for which this CRS object is valid.
  1. gml:verticalDatumType [0..1]    

Attributes

Used by

• Element gml:VerticalDatum
• Element gmx:ML_VerticalDatum via derived type gmx:ML_VerticalDatum_Type

Type inheritance chain

• gml:AbstractGMLType
  • gml:DefinitionType
    • gml:AbstractDatumBaseType
      • gml:AbstractDatumType
        • gml:VerticalDatumType
          • extended by gmx:ML_VerticalDatum_Type