1. Referencing Data to Real Locations

2. Objectives Explain what a map projection is
List the major categories of map projections
List spatial properties that may be distorted when different map projections are applied
Change the map projection for a data frame and describe its effects

3. Map Projection Types
Cylindrical
Conical
Planar

4. Cylindrical Projections

5. Conic Projections

6. Planar Projections

7. Understanding Distortion
Distortion cannot be avoided; we have to choose from distortion of
Shape
Area
Distance
Direction

8. Preserving Properties
If two properties are to be preserved then one is always direction
These properties are incompatible:

9. Equatorial (normal) Aspect

10. Transverse Aspect

11. Oblique Aspect

12. Classifying Projections

13. Choosing a Map Projection
Conformal (shape-preserving) maps
Topographic and cadastral
Navigation
Civil engineering
Weather

14. Choosing a Map Projection
Area-preserving maps
Population density
Land use
Quantitative attributes

15. Choosing a Map Projection
Scale-preserving maps no map preserves true distance for all measurements
Airline distances
Distance from epicenter of an earthquake
Cost calculations

16. Choosing a Map Projection

17. Thanks..