Geography Tools
Maps and Globes
Globes
• Advantages: They are an exact representation
of the Earth as it exists traveling through
space.
• Disadvantages:
– Not easily portable
– Can only see one half at a time since it is a sphere
Maps – 2 Dimensional, graphic
representations of the Earth’s surface
• Advantages:
– Can be drawn to any scale
– Easily Portable
• Disadvantages:
– Distortion occurs because you are trying to put a
round figure onto a flat surface
Dealing With Distortion
• To deal with distortion Cartographers use
different types of map projections.
• Cartographer – map maker
• Map Projection – way to draw a map that
reduces distortion
3 Types of Map Projections
• Planar Projections
• Conical Projections
• Cylindrical Projections
Planar Projection
• Also known as
Azimuthal
• The details of the
globe are projected
onto a plane (a flat
surface) yielding a
rectangular-shaped
map.
• It distorts size and
shape
• A line drawn through
the center to any
point is the shortest
possible line
Conical Projection
• Shows fairly accurate
shapes, but its distorts
along the edges…good
for displaying large land
masses
Cylindrical Projections
• 3 types of Cylindrical Projections:
– Mercator
– Homolosine
– Robinson
Mercator
• Shapes of continents are distorted at poles,
and somewhat compressed near the equator
Homolosine
• Shows accurate size and shapes of
landmasses, but distances between these
points are not correct (sometimes called
interrupted maps)
Robinson
• Shows the entire Earth, with almost true sizes
and shapes, but the shapes of the land near
the poles are flat
3 Types of Maps
• General Reference – usually topographic,
showing natural and man made features of
the earth
• Thematic – emphasize specific types of
information, such as climate, population, etc.
• Navigation – used by sailors, pilots, etc
Surveying
• Surveying is the first step in the map making
process
• Types of surveying:
– Remote Sensing – satellites or aerial photography
(most modern surveying is done this way)
– Out dated methods – exploring by sea and land
Satellites and Geography
• Landsat – a series of satellites that orbit more than
100 miles above the earth, they scan a path of land
115 miles wide while making their orbit, and can
scan the entire earth in 16 days
• GOES – Geostationary Operational Environment
Satellite – most often a weather satellite; it orbits at
the same speed as the earth’s rotation, in order to
constantly update information about that exact spot
on earth
(Satellites continued)
• GIS – Geographical
Information System –
collects and analyzes
many different types of
information; layers the
information to draw
conclusions
– Ex. A map that shows
population density,
cities, natural landforms,
and land use patterns
(Satellites continued)
• GPS – Global Positioning System – originally
developed for the military; uses 24 satellites
called NavStars to give an exact position
(latitude, longitude, elevation, and time)