1. GTECH 709 GIS Data Formats GIS data formats
GIS hierarchies GIS data models
Vector model
Raster model

2. GTECH 709 GIS hierarchies Chrisman’s spheres ANSI SPARC model
Levels of modeling

3. Chrisman’s Spheres

4. ANSI-SPARC Model for Software Development
GIS are systems to model the world
User Model
Conceptual Model
Operational Model

5. GIS Are Systems to Model the World
User Model – how we intuitively think
Conceptual Model
Operational Model
ANSI-SPARC Model for software development

6. GIS Are Systems to Model the World
User Model
Conceptual Model
Operational Model
ANSI-SPARC Model for software development
how we systematically define ideas

7. GIS Are Systems to Model the World
User Model
Conceptual Model
Operational Model
how we fuse systematic thinking into a technologically defined context

8. The ANSI/SPARC Model and Chrisman’s Spheres
application disciplines
context discipline
spatial modeling
conceptual modeling
logical data modeling
physical data modeling
OPERATIONAL
geoinformation theory
computer science

9. GTECH 709 GIS data models
Digital maps as models GIS data models

10. Digital Maps as Models Representing a complex reality
Continuous variation
Spatial Data: spatial, temporal and thematic
Data models
Geography = ƒ ( space, time, attributes)

11. Digital Maps as Models
Raster Model - The world as regular tessellations defined by areal property
Vector Model - The world as points, lines, areas and attributes….. making objects
Object Model - The world as interacting entities with spatial dimensions

12. GTECH 709 Vector data models
Spaghetti vs topological models Vector model details
Topology

13. Vector Data Models
Spaghetti model A file of spatial data that is a just a collection of co-ordinate strings. Each entity (or piece of spaghetti) is represented by one data entry. There is no topology.
Topological models Topology refers to the spatial relationships between objects. The topological model represents spatial relationships such as: length, area, connectivity, contiguity

14. The Vector Data Model

15. Vector Details
Nodes
Arcs
Polygons

16. Topology
Maintaining spatial relationships

17. Topology (2)

18. GTECH 709 The raster model
Raster components
Discrete vs. continuous

19. Raster Data Model

20. Cell

21. Column
Row

22. Cell With Value

23. Zones

24. No Data

25. Raster Attribute Table

26. Coordinate Space and the Raster Dataset

27. Discrete vs. Continuous

28. Resolution

29. Imagery

30. GTECH 709 GIS data formats
Shapefiles
Geodatabases
Coverages

31. GIS Data Formats

32. Shapefiles

33. (ESRI) Geodatabase

34. Organizing Vector Data
All features in a feature class have the same geometry type, the same attributes, and are located within a common geographic extent

35. Coverages
In ArcGIS
In MS Explorer