Coverage data Topology

What is coverage?

The coverage data model originated from ArcInfo, the first commercial GIS software launched by ESRI in 1981. Also known as the georelational data model, it is a model of the second generation of spatial data models.

Coverage spatial data Topological Relationship Model

Coverage uses "arc segments" as its core to construct a "polygon-Arc Segment Topology" and a "Arc Segment-node Topology", and achieves storage of the topological relationship of spatial data through the sharing mechanism. Coverage stores the Geographic Data "Topology", ensuring the precise relationship between polygon and arc segments, arc segments, and nodes.

 

In the core data organization of coverage, the two polygon A and B are expressed.

 

Arc #	Fnode #	Tnode #	Lpoly #	Rpoly #
AB	A	B	A	Null
BC	B	C	A	Null
CD	C	D	B	Null
De	D	E	B	Null
EF	E	F	B	Null
FC	F	C	B	A