Topology
Topic: Remote Sensing, GIS and GNSS · NCERT: Class 12, Ch 4 "Spatial Information Technology"
Meaning
Topology is the set of recorded links between vector features in a GIS. It notes which lines connect, which polygons (areas) share a boundary, and which areas lie inside others. Because of this, a GIS can answer questions such as "Which districts border this one?" or "Can I drive from this road to that one?" Topology is built after errors in the data, such as undershoots and overshoots, are corrected.
Example
In a GIS map of Kerala's districts, topology records that Ernakulam shares boundaries with Thrissur and Idukki. A query can then list every neighbour of a district without anyone looking at the map.
Don't confuse with
- Topography: topography is the shape of the land surface, its hills and valleys. Topology is about how map features connect to one another.
Related concepts
- Raster data model
- Vector data model
- Digitisation
- Scanner
- Charge-coupled device
- Georeferencing
- Raster-vector conversion
- Exact matching
- Hierarchical matching
- Fuzzy matching