3.2 Basic standards
77
The standard distinguishes between the geometry of time and the topology of
time. The geometry oftime has the four major classes:
• The instant: a certain time
• The period: time elapsed between two instances
• The order: sequence of instances
• The relative position: timely relation of earlier and later instances
The topology of time describes the timely connectivity between two or more occurrences. If two or more occurrences take place at one instant, that instant is called
anode. More precisely, the period between the occurrences is smaller than the resolution of the time. If two or more occurrences take place simultaneously during the
period, that period is called an edge.
Mare timely aspects are apart ofthe ISO 19136 (Geography Markup Language),
portrayed in chapter 4, section 6.
3.2.5 Georeference
This section addresses the ISO 19111 (Spatial referencing by coordinates), the
ISO/TS 19127 (Geodetic codes and parameters), the ISO 19112 (Spatial referencing
by geographic identifiers), and the ISO 19116 (Positioning services).
The ISO 6709: 1983 (Standard representation of latitude, longitude and altitude for
geographic point locations) has been developed by the ISO/lEC JTCl. In the year
2002 the maintenance of the ISO 6709 was transferred to the ISO/TC211. A systematic review of this standards revealed some shortcomings far geographic information
purposes. Most probably the ISO 6709 will be amended in the future.
3.2.5.1 Coordinate reference (ISO 19111)
The ISO 19111 (Spatial referencing by coordinates) models coordinate systems
and coordinate transformations for the ISO geomatics standards. This model contains
the horizontal and vertical coordinate references far geographic features. Coordinate
Reference Systems may be 1-, 2-, or 3-dimensional and do not change over time.
Ellipsoidal, Cartesian, and projected coordinate system
A Coordinate Reference System is a coordinate system that has a reference to the
earth by a so called datum. The ISO 19111 standardises the details in order to fully
define a Coordinate Reference System. The coordinate system may be an ellipsoidal
system, a Cartesian system, or a projected coordinate system. Projected coordinate
systems are used to realise map projections.
If it is an ellipsoidal system, the three coordinates are longitude, latitude, and ellipsoidal height. In most applications longitude and latitude are referred to as geo-
77
The standard distinguishes between the geometry of time and the topology of
time. The geometry oftime has the four major classes:
• The instant: a certain time
• The period: time elapsed between two instances
• The order: sequence of instances
• The relative position: timely relation of earlier and later instances
The topology of time describes the timely connectivity between two or more occurrences. If two or more occurrences take place at one instant, that instant is called
anode. More precisely, the period between the occurrences is smaller than the resolution of the time. If two or more occurrences take place simultaneously during the
period, that period is called an edge.
Mare timely aspects are apart ofthe ISO 19136 (Geography Markup Language),
portrayed in chapter 4, section 6.
3.2.5 Georeference
This section addresses the ISO 19111 (Spatial referencing by coordinates), the
ISO/TS 19127 (Geodetic codes and parameters), the ISO 19112 (Spatial referencing
by geographic identifiers), and the ISO 19116 (Positioning services).
The ISO 6709: 1983 (Standard representation of latitude, longitude and altitude for
geographic point locations) has been developed by the ISO/lEC JTCl. In the year
2002 the maintenance of the ISO 6709 was transferred to the ISO/TC211. A systematic review of this standards revealed some shortcomings far geographic information
purposes. Most probably the ISO 6709 will be amended in the future.
3.2.5.1 Coordinate reference (ISO 19111)
The ISO 19111 (Spatial referencing by coordinates) models coordinate systems
and coordinate transformations for the ISO geomatics standards. This model contains
the horizontal and vertical coordinate references far geographic features. Coordinate
Reference Systems may be 1-, 2-, or 3-dimensional and do not change over time.
Ellipsoidal, Cartesian, and projected coordinate system
A Coordinate Reference System is a coordinate system that has a reference to the
earth by a so called datum. The ISO 19111 standardises the details in order to fully
define a Coordinate Reference System. The coordinate system may be an ellipsoidal
system, a Cartesian system, or a projected coordinate system. Projected coordinate
systems are used to realise map projections.
If it is an ellipsoidal system, the three coordinates are longitude, latitude, and ellipsoidal height. In most applications longitude and latitude are referred to as geo-