Lecture 3

Question 1

georeferencing

Answer 1

principles/process of transforming spatial data from an arbitrary sys into a geographic or projected sys -> 3D to 2D, organize

Question 2

3 mathematical shapes of the earth as models

Answer 2

1. sphere
2. ellipsoid
3. geoid

Question 3

what does the ellipsoid model account for?

Answer 3

the earth’s rotation

Question 4

what does the geoid model account for/.

Answer 4

rock densities, equipotential gravity surfaces

Question 5

datum

Answer 5

collection of points or a reference point

Question 6

Gegraphic Coordinate Systems (GCS) (3)

Answer 6

• magnetic north and geographic north
• azimuth
• zenith and nadir

Question 7

Projected Coordinate systems

Answer 7

rep the curved earth on a flat plane

Question 8

what part of a projected map model is most accurate

Answer 8

the middle

Question 9

3 steps to the georef process

Answer 9

1. shape of earth in 3D
2. 2D map projection
3. transformation of one projection to another

Question 10

how the projection distort the earth? (4)

Answer 10

• angles
• areas
• distances
• directions

Question 11

polar/small location - surface, projection?

Answer 11

plane, azimuthal

Question 12

locations along equator - surface, projection?

Answer 12

cylinder, cylindrical

Question 13

upper latitude (eg. Canada) - surface, projection?

Answer 13

cone, conic

Question 14

UTM grid sys

Answer 14

world divided into 60 zones, 6 deg longitude each, 100km apart

Question 15

conversion from deg, min secs -> decimal deg

Answer 15

60s = 1 min, 60 min = 1 deg

Question 16

5 steps to georef

Answer 16

1. 3D
2. 2D
3. grids/UTM
4. placing self in grid
5. using it as a means of mgmt