A reference surface used as the basis of elevation, depth and time measurements.

bounding_ring (O, I: SET[0:?] ring(face))

Defines the set of rings which form the boundary of the face. For example, a polygon can be bounded by one ring while a face with a hole in it can be bounded by two rings. Each vertical_datum may be bounded by one or more ring. Inherited from face.


datum_for_axis (V: SET[0:?] vertical_depth_system_axis(measurement_datum))

The set of vertical depth system axes that use this vertical datum as their measurement datum. Each vertical_datum may be used by one or more vertical_depth_system_axis.


earth_model (I, V: SET[0:?] earth_model(spatial_object))

Indicates various earth models which include this spatial representation. Each vertical_datum may be part of one or more earth_model. Inherited from spatial_object.


initiate_offset (V: SET[0:?] vertical_datum_offset(initial_datum))

The set of vertical datum offsets that define this datum as the initial datum. These offsets are described as being normal to this vertical datum. For an offset being defined as from A to B, this describes the datum as being used as A. Each vertical_datum may initiate one or more vertical_datum_offset.


intersection_role (I, V: SET[0:?] space_time_operation(intersecting_object))

Indicates a space/time operation for which the object is involved as an intersecting agent. For projection, this is the screen on which an object is being projected. For proximity, this is the magnet object. Each vertical_datum may be the intersecting object for one or more space_time_operation. Inherited from topological_object.


local_vertical_datum (V: SET[0:?] local_vertical_datum(vertical_datum))

The local vertical datums that are defined to be parallel to this vertical datum. Each vertical_datum may define the orientation of one or more local_vertical_datum.


measured_depth_system_axis (V: SET[0:?] measured_depth_system_axis(vertical_datum))

These are the measured depth axes that use this vertical datum as the reference for vertical measurements, meaning measured depth is zero at this datum. Each vertical_datum may be used by one or more measured_depth_system_axis.


orient_axis (V: SET[0:?] vertical_depth_system_axis(normal_to_datum))

The set of vertical depth system axes that are defined to be oriented normal to this vertical datum. Each vertical_datum may define the orientation of one or more vertical_depth_system_axis.


other_composite_spatial_object (I, V: SET[0:?] other_composite_spatial_object(composite_object))

Defines the set of composite spatial objects of which this spatial object is a component. Each vertical_datum may be a component of one or more other_composite_spatial_object. Inherited from spatial_object.


primary_role (I, V: SET[0:?] space_time_operation(primary_object))

Indicates a space/time operation for which the object is involved as a primary agent. For degeneration, this object is being degenerated. For projection, this object is being projected onto another object. For proximity, this is the container object. Each vertical_datum may be the primary object for one or more space_time_operation. Inherited from topological_object.


primary_topological_relationship (I, V: SET[0:?] topological_relationship(primary_topological_object))

Indicates a topological relationship in which the topologic object has the role of primary agent. For an object intersection type of "inside" this is the containing role (e.g., if a city is inside a county then the county would be the primary agent). For all other object intersection types the roles are symmetrical and both relationships must be searched for a particular object. For example, if a wellbore and a formation overlap then either could be chosen as the primary agent with the other chosen as the secondary agent. Each vertical_datum may be primarily involved in one or more topological_relationship. Inherited from topological_object.


pty_area (I, V: SET[0:?] pty_area(face))

Each vertical_datum may have a property of one or more pty_area. Inherited from face.


pty_geometry_2d_face (I, V: SET[0:?] pty_geometry_2d_face(face))

Each vertical_datum may have a property of one or more pty_geometry_2d_face. Inherited from face.


pty_geometry_3d_face (I, V: SET[0:?] pty_geometry_3d_face(face))

Each vertical_datum may have a property of one or more pty_geometry_3d_face. Inherited from face.


secondary_topological_relationship (I, V: SET[0:?] topological_relationship(secondary_topological_object))

Indicates a topological relationship in which the object is in the role of secondary agent. For an object intersection type of "inside" this is the contained role (e.g., if a well is inside a field then the well would be the secondary agent). For all other object intersection types the roles are symmetrical and both relationships must be searched for a particular object. For example, if a wellbore and a formation overlap then either could be chosen as the secondary agent with the other chosen as the primary agent. Each vertical_datum may be involved in one or more topological_relationship. Inherited from topological_object.


shell (O, I: SET[0:?] shell(face))

Defines the shells of which this face is a component. Each vertical_datum may be a component of one or more shell. Inherited from face.


source_space_time_operation (I, V: BAG[0:1] space_time_operation(resulting_object))

Indicates the space/time operation from which a topological object was the result. For addition, this is the union of two objects. For degeneration, this is the degenerate object. Each vertical_datum may be the result of one space_time_operation. Inherited from topological_object.


terminate_offset (V: SET[0:?] vertical_datum_offset(terminal_datum))

The set of vertical datum offsets that define this datum as a terminal datum. This means the an offset being expressed from A to B would refer to this vertical datum as B. Each vertical_datum may terminate one or more vertical_datum_offset.


vertical_time_system_axis (V: SET[0:?] vertical_time_system_axis(vertical_datum))

The set of vertical time coordinate system axes that use this vertical datum as the location of origin of the time axis. Each vertical_datum may be used by one or more vertical_time_system_axis.

Local rules:

Abstract supertype:
Each VERTICAL_DATUM must be instantiated as one of its subtypes. These subtypes are: geodetic_datum, geoid, local_vertical_datum, vertical_reference_datum
Supertype path(s):
topological_object > spatial_object > simple_spatial_object > face > vertical_datum.

Entity replicated into subtype tables (@vertical_datum).

Referenced in Diagrams:

• CS2: Vertical Coordinate Axes