Map Projections

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Map Projections
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• Map Projections
• Putting a sphere on a flat surface messes up
  certain realities
• Distance
• Direction
• Shape
• Area
• Each map keeps one or two things true (pros), but
  the others are not accurate (cons).

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• Mercator
• Pros
• Direction
• Cons
• Shape
• Distance
• Area
• Africa is actually 14 times larger than Greenland!

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• Robinson
• Pros Cons
• Better area Directionand shape Distance

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• Goode homolosine
• Pros
• Shape
• Area
• Cons
• Direction
• Distance

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Latitude and Longitude
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Hemispheres
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Hemispheres
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The Earths Grid

• Any spot on Earth can be plotted with latitude
  and longitude.

• Lines of latitude run east-west
• Lateral means side-to-side (lateral pass)
• Also called parallels
• Measured in degrees of N or S
• 0 latitude is the Equator
• 90 N is the North Pole
• 90 S is the South Pole

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Latitude
Measure North
Equator
Measure South
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Upper Latitudes
Lower Latitudes
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Longitude

• Lines of longitude run north-south
• All lines of longitude are long
• Also called meridians
• Measured in degrees of E or W
• 0 longitude is the Prime Meridian
• Runs through Greenwich, England, just outside
  London
• 180 E/W is the International Date Line

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Longitude
Prime Meridian
Measure East
Measure West
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35º N
34º 5 N
34º N
18º E
19º E
18º 25 E
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The Earths Grid

• A specific location uses N or S and W or E for
  each coordinate pair
• Three ways to show coordinates
• Degrees, minutes, seconds 30, 15, 45 N 54,
  20, 10 W
• 1 degree 60 minutes 1 minute 60 seconds
• Note This is not in reference to time!
• Degminsec 301545N, 542010W

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Three ways to show coordinates continued

• 301545N, 542010W
• Decimals 30.2625, -54. 336111
• (south and west are negative numbers)
• Found by dividing minutes/60
• i.e. 15 minutes 15/60 .25
• And then seconds/3600
• i.e. 45 seconds 45/3600 .0125
• Add the two together
• .25 .0125 .2625

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Latitude and Longitude

• Together, any point on Earth can be plotted on a
  map
• Use both coordinates together
• Latitude, longitude
• 40 N, 85 E 10 S, 15 W
• Walton 335920.663 N, 842630.718 W
• This is the Front Office

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Why Degrees, Minutes, Seconds?

• A circle is 360
• When computing various angles, we base our
  measurements on degrees.
• i.e. Right angles are 90
• An angle between 90 and 91 require requires
  minutes and seconds to find the specific angle.
• In 3D, we add the Z Axis,
• which requires the second degree measurement