8. Projections And Coordinate Systems

Front 1

list the 3 types of map projections

Back 1

1. cylindrical
2. conical
3. planar

Front 2

cylindrical projections

Back 2

Mercator

Front 3

conical projections

Back 3

perspective conic

Front 4

planar projections

Back 4

orthographic

Front 5

which type of projection is good for the poles?

Back 5

planar/orthographic

Front 6

where is the line of least distortion on a cylinder projection?

Back 6

Front 7

where are the lines of least distortion on normal, transverse, and oblique cylindrical projections?

Back 7

Front 8

where is the line of least distortion on a conic projection?

Back 8

Front 9

where is the line of least distortion on a planar projection?

Back 9

Front 10

"all maps lie flat and ______________"

- _______________

Back 10

"all maps lie flat and all flat maps lie"

- Mark Monmonier

Front 11

all projections have....

Back 11

some distortion

Front 12

specific projections minimize distortion in one or more of the following areas...

Back 12

1. area
2. distance
3. direction
4. shape

Front 13

[ specific projections minimize distortion in one or more of the following areas... ]

area

Back 13

equivalent or equal area

Front 14

[ specific projections minimize distortion in one or more of the following areas... ]

distance

Back 14

equidistant or true distance

Front 15

[ specific projections minimize distortion in one or more of the following areas... ]

direction

Back 15

azimuthal or true direction

Front 16

[ specific projections minimize distortion in one or more of the following areas... ]

shape

Back 16

conformal or true shape

Front 17

[ map distortion examples ]

unprojected

Back 17

UTM if you unrolled latitude and longitude grid and spread it out...just a flat way of looking at the globe

Front 18

[ map distortion examples ]

Mercator

Back 18

based on same principals of unprojected...

Front 19

what are the 2 most important projections to know?

Back 19

1. Lambert conformal conic
2. transverse Mercator

Front 20

Lambert conformal conic and transverse Mercator are both ____________

Back 20

conformal projections (preserve shape)

Front 21

Lambert conformal conic

Back 21

distances true only along the standard meridian or standard parallels

Front 22

transverse Mercator

Back 22

distortion of distance, area, and direction increase with distance from the central meridian or standard parallels

Front 23

which type of projection is this?

Back 23

Lambert conformal conic

Front 24

which type of projection is this?

Back 24

transverse Mercator

Front 25

what is a coordinate system?

Back 25

2-dimensional model of the earth's surface

Front 26

what 4 things are coordinate systems defined by?

Back 26

1. a particular map projection
2. an origin that is referenced to a known point on the ellipsoid
   - latitudinal point of origin → standard parallel
   - longitudinal point of origin → central
   meridian
3. a measurement unit (usually meters or feet)
4. offset
   - false easting
   - false northing

Front 27

common coordinate systems

Back 27

1. state plane
   - transverse Mercator (GA) or
   - Lamber conformal conic (TN)
2. UTM

Front 28

how many UTM zones are there?

Back 28

60

Front 29

UTM is much more common for...

Back 29

state and smaller things

Front 30

which coordinate system is this?

Back 30

state plane

Front 31

which coordinate system is this?

Back 31

UTM

Front 32

[ Georgia State Plane ]

Georgia Coordinate System

Back 32

• NAD 27

• measurement units → feet

• false easting → 500,000 feet

Front 33

[ Georgia State Plane ]

Georgia Coordinate System of 1985

Back 33

• NAD 83
• measurement units → meters
• false easting
  - 200,000 m for east zone
  - 700,000 m for west zone
  

Front 34

[ practical applications ]

select a coordinate system with ____________ for your project area

Back 34

the least distortion

Front 35

[ practical applications ]

make sure _________ and _________ (on a given project) are using the same _______________

Back 35

make sure all data and all people (on a given project) are using the same coordinate system