文档介绍：An Introduction To Geographical Information Systems (GIS)
by Harold Reynolds
December 18, 1997
Table of Contents
An Introduction To Geographical Information Systems (GIS)..........................3
What is a Geographical Information System?............................................................................3
Who would use a GIS?................................................................................................................3
How this relates to us!.................................................................................................................3
So what's so special about geographic data?...............................................................................4
So how can we store geographic data?.......................................................................................4
In Layers.................................................................................................................................4
Raster data model...................................................................................................................4
Vector Data Model.................................................................................................................6
Object-oriented Models..........................................................................................................6
What can a GIS do?.....................................................................................................................7
Point-in-Polygon Queries.......................................................................................................9
Proximity-based Queries........................................................................................................9
Network Queries...................................................................................................................11
Thematic Maps..................................................