Topology studies properties of geometry (such as point, line, and area objects) that remain invariant under transformations like bending or stretching. Through topology processing or validation of simple datasets (i.e., point, line, and region datasets), and modifying generated topology errors, we can ensure digitized geometry adheres to user-specified topology. This forms the foundation for subsequent operations like constructing region datasets, network datasets, or performing network analysis.
SuperMap provides two main topology processing methods: The first is topology processing, which exclusively checks line datasets (or network datasets) and automatically corrects topology errors. The second is validate topology, offering detailed rules for meticulous checks on point, line, and region datasets. The system saves topology errors to new result datasets, allowing users to manually modify them accordingly.
SuperMap provides rules for both topology processing and topology validation. In SuperMap, topology errors include geometry errors within single datasets and cross-dataset geometry errors. These errors encompass self-intersections, self-overlaps of point/line/region objects, and spatial relationships between them including intersection, overlap, containment, and adjacency.
Establishing topology with specified rules, followed by topology processing and validation, ensures maximum data quality. Topology helps detect improperly connected lines, unclosed polygons, and other errors in digital maps. By building topological relationships to correct spatial relationships between features, we ensure data integrity and accuracy.
Topology Processing Rules
During spatial data collection and editing, errors inevitably occur. For example, duplicate digitization of nodes/lines, gaps/intersections between adjacent polygons, or unclosed shapes may produce pseudo nodes, redundant nodes, dangling lines, or duplicate lines. These topology errors cause discrepancies between collected spatial data topology and real-world feature topology, affecting subsequent data processing, analysis, and overall data quality. Moreover, these errors are often numerous, hidden, and hard to identify manually. Therefore, topology processing is essential to fix these redundancies and errors. For details, see Topology Processing Rules.
Topology Validation Rules
Topology validation identifies objects in point/line/region datasets that violate topology rules, both within datasets and between different dataset types. It primarily serves data editing and topology analysis preprocessing.
SuperMap offers robust topology validation capabilities: 7 topology rules for point datasets, 15 for line datasets, and 10 for region datasets. Additionally, 5 cross-dataset topology rules are provided, meeting comprehensive validation requirements.
For details, refer to Topology Validation Rules.