Topology is the study of the properties of Geometry (such as point, line, and face objects) that remain unchanged under transformations such as bending or stretching. You can ensure that the digitized Geometry follows the user-specified Topology by performing a Topology Processing or check on the Simple Dataset (i.e., point, line, Region Dataset) and modifying the resulting Topology error. It is the basis for subsequent operations such as Region Dataset, Network Dataset, or Network Analysis.
There are two main Topology Processing methods provided by SuperMap: one is Topology Processing, Topology Processing only checks the Line Dataset (or Network Dataset), and then the system will change the wrong Topology in the Dataset; The other is Topology Check, which provides detailed rules to perform more detailed checks on points, lines, and Region Datasets, and the system will save the Topology error to a new Result Dataset. Users can modify the Result Dataset.
SuperMap provides rules for Topology Processing and rules for Topology Check. In SuperMap, Topology error includes Topology error of Geometry in a single Dataset and Geometry Topology error between different Datasets; The Topology error between Geometry includes the self-intersection and self-overlap of point, line and face, and the relationship among them, including the spatial relationship of intersection, overlap, inclusion and connection.
The quality of data can be guaranteed to the greatest extent by establishing Topology according to the specified rules and performing Topology Processing and Topology Check. Topology can be used to detect incorrectly connected lines, incorrectly closed polygons, and other Topology errors on digital maps. Correcting the incorrect spatial relationship between elements through Build Topological Relationships can ensure the integrity and correctness of data.
Topology Processing rule
In the process of collecting and editing Spatial Data, some errors will inevitably occur. For example, the same node or the same line is digitized twice, and the adjacent surface objects are cracked or intersected or not closed in the acquisition process. These errors often lead to Topology errors such as false nodes, redundant nodes, suspended lines and repeated lines. As a result, the Topology of the collected Spatial Data does not match the Topology of the actual ground objects, which will affect the subsequent Data Processing and analysis work, as well as the quality and availability of the data. In addition, these Topology errors are usually large and hidden, which are not easy to be identified and removed by manual methods. Therefore, Topology Processing is needed to fix these redundancies and errors. Please refer to the Topology Processing rule for more details.
Topology Check rule
Topology Check is to check out the objects of points, lines, Region Dataset itself and different types of Dataset that do not conform to Topology Rules. It is mainly used for Edit Data and topology analysis preprocessing.
SuperMap provides a powerful Topology Check feature, Provides 7 Topology Rules for Point Dataset, 15 Topology Rules for Line Dataset, and 10 Topology Rules for Region Dataset. It also provides five Topology Rules for different types of Dataset, which can basically meet all the needs of Topology Check.
Please refer to the Topology Check rule for more details.