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Maps, Etc.
What are they, why do we use them, and how do we use them
Globes• 3 dimensional representation of the Earth
• Advantages – exactly as it is, just smaller
• Disadvantages – not easily portable, since it is a sphere, we can only see half at a time
Maps
• 2 Dimensional Representations of Earth, or just a portion
• Advantages: easily portable; can be drawn to any scale
• Disadvantages: DISTORTION – because you are trying to make a round thing flat
Map Projections
• Projections help us overcome/reduce distortion
• Planar (azimuthal) • Conical – shows pretty
accurate shapes and sizes of landmasses, but distorts the edges [good for showing just one big land mass
• Cylindrical – Shows the entire Earth, and there are 3 types
Types of Cylindrical Maps• Mercator – shapes of
continents are distorted at the poles (tops/bottoms), and compressed near equator
• Homolosine – accurate size and shape, but distances are wrong (interrupted)
• Robinson – entire earth, good shapes and sizes, but shape of land at the poles is flat (the one on the wall)
Uses/Types of Maps• General Reference – topographic
• Thematic – specific types of information shown, like climate or population
• Navigation – used by sailors and pilots
Surveying
• This is what you do to gather the info you need to make a map
• It all was manual in the past, now we use satellites and airplanes
Satellite Systems
• Landsat – series of satellites that update the entire Earth every 16 days
• GOES – Geostationary Operational Environment Satellite
More Satellite and Map Stuff
• GIS – Geographic Informational System – this layers information on to a map
• GPS – Global Positioning System – uses 24 Nav Stars to tell you exactly where you are [latitude, longitude, elevation, time]