76
3 Non-geometry standards
associations between features that contain the information regarding which feature is
above the other or if both are on the same level. In this case, the association type
(class GF _ AssociationType) would be "intersection", and the association roles (class
GF _ AssociationRole) would be under, over, or level respectively.
In some cases, it may be advisable to impose constraints to the definition of a feature. A theoretical example may be that a feature of type curve must not have more
than 1000 points. The GFM allows the formulating of these constraints (class
GF _ Constraint).
An application schema is usually created by the definition of the features. All details are collected in a feature catalogue. The methodology for building feature catalogues is covered by ISO 19110.
3.2.3 Spatial schema (ISO 19107)
ISO 19107 (Spatial schema) is a standard to describe the geometry and the topology of geographic information. This standard comprises a comprehensive definition
of the geometric elements required to build a geographic dataset.
The standard primarily addresses vector data up to three dimensions. For the 2dimensional case, the standard includes provisions that guarantee a seamless coverage of a complete area.
The ISO 10107 defines a method to describe the position of a geometric element.
A position is named DirectPosition. It includes the coordinates such as x, y, and z
depending on the Coordinate Reference System of the dataset and its dimension.
This method is used throughout other important standards of the ISO 19100 family
such as the ISO 19123 (Schema for coverage geometry and functions).
This standard does not address the graphic portrayal of the geometric elements.
The chapter 4, section 3 "Spatial schema" contains a detailed description of ISO
19107.
3.2.4 Temporal schema (ISO 19108)
As far as geomatics is concemed, temporal characteristics are standardised in ISO
19108 (Temporal schema). This standard is not an independent standard for the description of time, but rather an addition to the existing standards (lS005 1992).
Many geographic applications require a time stamp related to the physical reality and
therefore, the standard deals with the valid time which is the time when the event occurred in the abstracted reality. The standard does not address the transaction time
when the data becomes available in a database.
In many applications, the time is handled as a metadata element only. More advanced applications require the time as a further dimension. This enables the modelling of the behaviour of a feature as a function of time, like a satellite's position
along its orbit.
3 Non-geometry standards
associations between features that contain the information regarding which feature is
above the other or if both are on the same level. In this case, the association type
(class GF _ AssociationType) would be "intersection", and the association roles (class
GF _ AssociationRole) would be under, over, or level respectively.
In some cases, it may be advisable to impose constraints to the definition of a feature. A theoretical example may be that a feature of type curve must not have more
than 1000 points. The GFM allows the formulating of these constraints (class
GF _ Constraint).
An application schema is usually created by the definition of the features. All details are collected in a feature catalogue. The methodology for building feature catalogues is covered by ISO 19110.
3.2.3 Spatial schema (ISO 19107)
ISO 19107 (Spatial schema) is a standard to describe the geometry and the topology of geographic information. This standard comprises a comprehensive definition
of the geometric elements required to build a geographic dataset.
The standard primarily addresses vector data up to three dimensions. For the 2dimensional case, the standard includes provisions that guarantee a seamless coverage of a complete area.
The ISO 10107 defines a method to describe the position of a geometric element.
A position is named DirectPosition. It includes the coordinates such as x, y, and z
depending on the Coordinate Reference System of the dataset and its dimension.
This method is used throughout other important standards of the ISO 19100 family
such as the ISO 19123 (Schema for coverage geometry and functions).
This standard does not address the graphic portrayal of the geometric elements.
The chapter 4, section 3 "Spatial schema" contains a detailed description of ISO
19107.
3.2.4 Temporal schema (ISO 19108)
As far as geomatics is concemed, temporal characteristics are standardised in ISO
19108 (Temporal schema). This standard is not an independent standard for the description of time, but rather an addition to the existing standards (lS005 1992).
Many geographic applications require a time stamp related to the physical reality and
therefore, the standard deals with the valid time which is the time when the event occurred in the abstracted reality. The standard does not address the transaction time
when the data becomes available in a database.
In many applications, the time is handled as a metadata element only. More advanced applications require the time as a further dimension. This enables the modelling of the behaviour of a feature as a function of time, like a satellite's position
along its orbit.