82
3 Non-geometry standards
(ITRS), the Earth Gravity Model (EGM) 96 geopotential model, and the Universal
Transverse Mercator (UTM) Coordinate Reference System.
3.2.5.3 Geographie identifiers (ISO 19112)
The position of geographie features is often described through their spatial relation to other geographie features. This relation may be a containment, a local measurement, or a loose relation. An example of a containment is a city within a province; an example of a local measurement is the distance to the next major road
intersection, and an example of a loose relation is a restaurant "between the museum
and city hall". A typical application is the partitioning of an area using postal codes.
These types ofpositions are addressed in the ISO 19112 (Spatial referencing by geographie identifiers).
All positions are related to a spatial reference system. The spatial reference system comprises a subdivision of a territory such as the hierarchy "province - city -
address". The core element ofthe reference system is a gazette er that adds a descriptive position to every geographie feature in the territory.
A gazetteer is a file that contains a master record for every geographie feature and
the related descriptive position. If required, any descriptive position can be related to
coordinates according to ISO 19111 (Spatial referencing by coordinates). The coordinates may be expressed as point coordinates or as abounding box for curves or
surfaces.
A location type according to ISO 19112 is a territorial unit of the spatial reference
system. Examples of location types are an administrative area, town, locality, street,
and property. A geographie feature in this context is called a location instance. A
geographie feature is listed in the gazetteer and is related to one or more location
types. For example, the city hall is a geographie feature that has one record in the
gazetteer and this record contains a position that may be expressed in three ways: as
an address, or as a containment in the city, or as a containment in the province.
Gazetteer
Spatial refereneing system
using geographie identifiers
<>
Loeation instanee
Loeation type
Fig. 3.13. Spatial referenee system using geographie identifiers (IS044 2001)
3 Non-geometry standards
(ITRS), the Earth Gravity Model (EGM) 96 geopotential model, and the Universal
Transverse Mercator (UTM) Coordinate Reference System.
3.2.5.3 Geographie identifiers (ISO 19112)
The position of geographie features is often described through their spatial relation to other geographie features. This relation may be a containment, a local measurement, or a loose relation. An example of a containment is a city within a province; an example of a local measurement is the distance to the next major road
intersection, and an example of a loose relation is a restaurant "between the museum
and city hall". A typical application is the partitioning of an area using postal codes.
These types ofpositions are addressed in the ISO 19112 (Spatial referencing by geographie identifiers).
All positions are related to a spatial reference system. The spatial reference system comprises a subdivision of a territory such as the hierarchy "province - city -
address". The core element ofthe reference system is a gazette er that adds a descriptive position to every geographie feature in the territory.
A gazetteer is a file that contains a master record for every geographie feature and
the related descriptive position. If required, any descriptive position can be related to
coordinates according to ISO 19111 (Spatial referencing by coordinates). The coordinates may be expressed as point coordinates or as abounding box for curves or
surfaces.
A location type according to ISO 19112 is a territorial unit of the spatial reference
system. Examples of location types are an administrative area, town, locality, street,
and property. A geographie feature in this context is called a location instance. A
geographie feature is listed in the gazetteer and is related to one or more location
types. For example, the city hall is a geographie feature that has one record in the
gazetteer and this record contains a position that may be expressed in three ways: as
an address, or as a containment in the city, or as a containment in the province.
Gazetteer
Spatial refereneing system
using geographie identifiers
<>
Loeation instanee
Loeation type
Fig. 3.13. Spatial referenee system using geographie identifiers (IS044 2001)