The offset between two vertical datums in the direction normal to the initial vertical datum. These offsets provide a vertical link to the Earth when at least one related offset is based upon a vertical datum tied to the Earth. The offset may be defined through a selected point, when appropriate.

end_time (O, K, I: ndt_date_tod)

End time of the association. Inherited from transient_association.


start_time (O, K, I: ndt_date_tod)

Start time of the association. Inherited from transient_association.


earth_point (O, K: earth_point(vertical_datum_offset))

This is an earth point that is defined as being on the line normal to the initiating datum in which the offset is described. This allows non-parallel datums to be described with offsets at various points. Each vertical_datum_offset may be defined at one earth_point.


initial_datum (M, K: vertical_datum(initiate_offset))

The vertical datum which is the initiation of an offset between two vertical datums. The offset is described normal to this datum. For an offset from A to B, this points to A. Each vertical_datum_offset must be initiated with one vertical_datum.


terminal_datum (M, K: vertical_datum(terminate_offset))

The vertical datum which is the termination of the offset between two vertical datums. When the offset is expressed from A to B, this defines B. Each vertical_datum_offset must be terminated at one vertical_datum.


source (M, I: ref_source)

The provider of this instance of reference information. If this instance is provided by POSC, then this attribute must be "POSC". Each vertical_datum_offset must provided by one ref_source. Inherited from reference_behavior.


description (O, I: ndt_comment)

A description of the transient association. Inherited from transient_association.


duration (O, I: ndt_time)

Defines the duration of the association expressed in any valid units of time. Inherited from transient_association.


length_offset (O: ndt_length_midrange)

Length of the offset from the initial vertical datum to the terminal vertical datum. This length is measured in the vertical direction, positive upwards.


status (O, I: ndt_instance_status) (0644)

The status of this instance in the version of Epicentre running in a data store. This is an enumerated datatype for which the following are the possible values: current, provisional, deprecated. Current - use without restriction. Provisional - use with caution, this value is for comment and may not appear in future releases of Epicentre. Deprecated - avoid use if possible, it is planned to remove this value in the next major release of Epicentre. Inherited from reference_behavior.


time_offset (O: ndt_seismic_time)

One way travel time of the offset from the initial vertical datum to the terminal vertical datum. This travel time is measured in the vertical direction, positive upwards.


caused_by (O, I: activity(cause_association))

Specifies the activity which establishes this association. Each vertical_datum_offset may be caused by one activity. Inherited from transient_association.


data_collection (I, V: SET[0:?] data_collection(collection_content))

Indicates the data collections that include this instance of E and P data. Each vertical_datum_offset may be a member of one or more data_collection. Inherited from e_and_p_data.


graphical_element (I, V: SET[0:?] graphical_element(depicted_object))

Specifies one or more graphical elements which are depicting this data item. Each vertical_datum_offset may be depicted by one or more graphical_element. Inherited from e_and_p_data.


ref_transient_period (O, I: ref_transient_period) (1222)

The type of period over which the property applies, such as day, month, quarter, cumulative, etc. Inherited from transient_association.


source_reference (O, I: ref_source_reference)

The reference used by source to provide the standard instance, such as Petroleum Industry Data Dictionary (PIDD), Websters Ninth New Collegiate Dictionary, etc. Each vertical_datum_offset may documented by one ref_source_reference. Inherited from reference_behavior.


terminated_by (O, I: activity(terminate_association))

Specifies the activity which established the termination of a transient association between two objects. Each vertical_datum_offset may be terminated by one activity. Inherited from transient_association.


version (O, I: ref_epicentre_version) (0644)

Describes the version of Epicentre when this status was assigned to this instance of reference behavior Each vertical_datum_offset may version one ref_epicentre_version. Inherited from reference_behavior.

Local rules:

Uniqueness Constraint
end_time, start_time, earth_point, initial_datum, terminal_datum
Different Related Instance
Each VERTICAL DATUM OFFSET cannot be initiated with and be terminated with the s ame instance of VERTICAL DATUM.
[I: transient_association] Instance Value Constraint (1259)
If REF_TRANSIENT_PERIOD is EVENT, then both START_TIME and END_TIME must either be blank or be identical.
[I: transient_association] Instance Value Constraint
If REF_TRANSIENT_PERIOD is either YEAR TO DATE, MONTH TO DATE or CUMULATIVE, then END_TIME must be instantiated.
[I: transient_association] Instance Value Constraint
If REF_TRANSIENT_PERIOD is ANNUAL, SEMIANNUAL, QUARTER, MONTHLY, DAILY, or HOURLY, then either both START_TIME and END_TIME are blank or both must be instantiated.
Supertype path(s):
e_and_p_data > association > transient_association > vertical_datum_offset.
reference_behavior > vertical_datum_offset.

Entity projects as table VERT_DTM_OFST.

Referenced in Diagrams:

• CS2: Vertical Coordinate Axes