166 4 Geometry standards
composition, and elevation. A value or deseription of a eontinuous phenomenon is
only meaningful at a particular position in space and possibly time. Temperature, for
example, takes on speeifie values only at defined locations whether measured or interpolated from other locations.
4.5.1 Overview over ISO 19123
A eoverage is a subtype of a geographie feature (class GF _FeatureType, ISO
19109) and is assoeiated to a Coordinate Reference System aeeording to ISO 19111.
4.5.2 Description of the discrete coverage classes of ISO 19123
A diserete coverage eonsists of individual geometrie objects in which an interpolation between those objeets is not allowed.
CV_DiscretePointCoverage
A discrete point eoverage (class CV _ DiseretePointCoverage) is a set of irregulady distributed points and their attributes. The prineiple use of diserete point eoverages is to provide a basis for eontinuous eoverage functions.
An example for a diserete point eoverage would be a small scale map showing eities and their population. In this ease it is not feasible to interpolate between the
points of the eities .
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• •
•
•
•
•
•
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Fig. 4.61. Discrete point coverage
CV_DiscreteCurveCoverage
A diserete eurve (class CV J)isereteCurveCoverage) eoverage is eharaeterized by
a finite spatiotemporal domain eonsisting of eurves that may be elements of a network.
An example of a diserete eurve eoverage is a road-network where the eoverage
assigns a route number, a name, a pavement width, and a pavement material type to
eaeh segment ofthe road system.
composition, and elevation. A value or deseription of a eontinuous phenomenon is
only meaningful at a particular position in space and possibly time. Temperature, for
example, takes on speeifie values only at defined locations whether measured or interpolated from other locations.
4.5.1 Overview over ISO 19123
A eoverage is a subtype of a geographie feature (class GF _FeatureType, ISO
19109) and is assoeiated to a Coordinate Reference System aeeording to ISO 19111.
4.5.2 Description of the discrete coverage classes of ISO 19123
A diserete coverage eonsists of individual geometrie objects in which an interpolation between those objeets is not allowed.
CV_DiscretePointCoverage
A discrete point eoverage (class CV _ DiseretePointCoverage) is a set of irregulady distributed points and their attributes. The prineiple use of diserete point eoverages is to provide a basis for eontinuous eoverage functions.
An example for a diserete point eoverage would be a small scale map showing eities and their population. In this ease it is not feasible to interpolate between the
points of the eities .
• • • •• •
• •
• •
•
•
•
•
•
•
Fig. 4.61. Discrete point coverage
CV_DiscreteCurveCoverage
A diserete eurve (class CV J)isereteCurveCoverage) eoverage is eharaeterized by
a finite spatiotemporal domain eonsisting of eurves that may be elements of a network.
An example of a diserete eurve eoverage is a road-network where the eoverage
assigns a route number, a name, a pavement width, and a pavement material type to
eaeh segment ofthe road system.