Topology studies the property of remaining unchanged when geometric objects (point, line and region objects) were bended or stretched. You can ensure that the digital geometric objects follow the specified topology relations by topology processing and checking the simple datasets (point, line and region datasets) and modifying the topology errors. It is the basic that construct region dataset, network dataset or conduct the network analysis.

There are two methods of topology processing provided by SuperMap: topology processing only check the line datasets (or the network datasets) and the system will modify the topology errors in dataset; The other is topology checking. The topology checking provides detail rules to check the point, line and region datasets. System will save the topology errors to the new result dataset. Users can modify compared to the result dataset.

Build the topology relation and conduct the topology processing and checking according to the specified rules. You can ensure the quality of the data. The topology relation can be used to find the lines that aren't connected properly, the unclosed polygons and other topology errors in digital map. Modify the incorrect spatial relation by constructing topology relations, and you can ensure the integrity and accuracy of data.

SuperMap provides 7 methods in topology processing and 29 methods in topology checking. In SuperMap, the topology errors include two types: the topology errors of geometric objects in single dataset or in different datasets; The topology errors in geometric objects contain self intersection, self overlap and the correlations in three (include intersection, overlap, containing, connecting and other spatial relations).

Main Contents:

Introduce the rules and usages used in topology processing, including removing pseudo nodes, redundant vertices, duplicated lines, extending undershoots, merging adjacent endpoints and intersecting arcs in detail.

Introduce the rules and usages used in topology processing in detail. The topology checking provides 6 rules for point datasets, 13 rules for line datasets and 10 rules for region datasets, which can meet all the topology checking requirements.

Introduce the methods and steps for topology preprocessing in details, including inserting vertices, snapping to vertices, changing directions of polygons, etc.

Introduce how to check and fix for the line datasets or network datasets.

Introduce how to use the topology rules provided by SuperMap to check the geometric objects that don't fit the rules in or between datasets.

Introduce how to use line datasets or network datasets to construct region datasets.

Introduce how to use line datasets or network datasets to construct network datasets.