1. Map Projections

2. The Earth needs to be transformed.
The Earth is a spheroid
A mathematical conversion must be used to create a flat map sheet from the three-dimensional surface.
The Earth needs to be transformed.

3. Projection is a mathematical procedure of representing the globe on a flat surface.

5. How do you put a round surface on a flat paper ?
Mathematically, a projection is a process of transforming global location to a planar position.
Planar coordinate systems:
Have two dimensions,
X measures distance in a horizontal direction
Y measures distance in a vertical direction
Measures of length, angle, and area are constant across the dimension

6. Different Acronyms UTM = Universe Transverse Mercator
WGS = World Geodetic System
NAD = North American Datum
GRS = Geodetic Reference System
Oblate Ellipsoid or Spheroid

7. The Earth is not a ball 1924 measurements were: e = 6,378,206.4
P = 6,356,538.8 m
Or: f = 1/297
1980 (GRC80)
Geodetic Reference System
1983 (NAD83)
WGS84
World Geodetic System
F = 1/300 e p
F = 1-p/e
NAD1927
(North American Datum)

8. Any representation of the earth’s surface in two dimensions:
Causes some distortion:
4 types of distortion:
Shape
area
distance
direction
Different projections produce different distortions

9. Some commonly used map projections in the U.S. and North America

10. UTM a Planar Coordinate System

11. Latitude and Longitude
Is a geographic referencing system
NOT a projection

13. UTM Zone 13

14. Lambert Conformal Conic

15. Albers Equal-Area Conic

19. Assignment – Projections of the World
Create a map showing at least 4 different world projections (different data frames).
Indicate on the map each projection
Include a title, and scale of each map
Design your layout to maximize your space
Print your map on 17 x 11 inch paper