4.5 Schema for coverage geometry and functions (ISO 19123)
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4.5.3 Description of the continuous coverage classes of ISO 19123
A continuous coverage is a combination of a discrete coverage with an interpolation function that fills the space and eventually the time in between. For the interpolation the ISO 19123 defines the following methods:
Table 4.1. Relation between interpolation methods and coverage types
Interpolation method
Nearest neighbour interpolation
Linear interpolation
Quadratic interpolation
Cubic interpolation
Bilinear interpolation
Biquadratic interpolation
Bicubic interpolation
Lost area interpolation
Barycentric interpolation
Type of coverage that uses this interpolation method
any coverage
segmented curve coverage
segmented curve coverage
segmented curve coverage
quadrilateral grid coverage
quadrilateral grid coverage
quadrilateral grid coverage
discrete point coverages
TIN coverage
CV_ ThiessenPolygonCoverage
A Thiessen polygon coverage (CV _ThiessenPolygonCoverage) partitions the
space using Thiessen polygons. Thiessen polygons are closed polygons around
points of an irregularly distributed point set. For any position within a Thiessen
polygon its centre point is the closest of the whole point set. Thiessen polygons are
defined in the 2-dimensional space only. They make it possible to apply lost area interpolation to a point set. They are also used for one step in the computation of a TIN
for a given point set.
Fig. 4.66. Thiessen polygon network (lS053 2002)