Geography 2122A/B Chapter Notes -Developable Surface, Map Projection

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Published on 16 Apr 2013
School
Western University
Department
Geography
Course
Geography 2122A/B
Professor
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Map Projection
- a map projection is a geometrical transformation of the
earth’s spherical or ellipsoidal surface onto a flat map surface
Map Projection Properties
- Scale
- Completeness
- Correspondence relation
- Continuity
Map Projection Properties: Scale
- Scale
o The stated scale is true only at selected points or along
particular lines
- There are two map scales:
o Principal scale: the scale of generating globe (no
variation)
o Actual Scale: the scale we measure at any point on the
map. Scale variations here is the result of geometric
distortion
o SF = Actual Scale / Principal scale
Map Projections Classification Categories
- Projectin families based on map projection surface
o Projection surface
o Developble Surface: the flat surface that the earths
features are projected onto
o Three projections families based on the developable
surface:
Planar
Conic
Cylindrical

Document Summary

A map projection is a geometrical transformation of the earth"s spherical or ellipsoidal surface onto a flat map surface. Scale: the stated scale is true only at selected points or along particular lines. There are two map scales: principal scale: the scale of generating globe (no variation, actual scale: the scale we measure at any point on the map. Scale variations here is the result of geometric distortion: sf = actual scale / principal scale. Projectin families based on map projection surface: projection surface, developble surface: the flat surface that the earths features are projected onto, three projections families based on the developable surface: