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Map projections. By: Ms. A. McFadden. Azimuthal/Polar projections Azimuthal equidistant projections are sometimes used to show air-route distances. Distances measured from the center are true. Distortion of other properties increases away from the center point . Maps are circular.
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Map projections By: Ms. A. McFadden
Azimuthal/Polar projectionsAzimuthal equidistant projections are sometimes used to show air-route distances. Distances measured from the center are true. Distortion of other properties increases away from the center point .Maps are circular.
Cylindical ProjectionsBoth meridians and parallels appear as straight lines. But, since meridians converge at the poles there is large distortion in shape and scale the closer you get to 90 degrees north or south. Maps are rectangular.
The Peters projection is a cylindrical equal-area projection that de-emphasizes area exaggerations in high latitudes by shifting the standard parallels to 45 or 47 degrees.
The Mercator projection has straight meridians and parallels that intersect at right angles. Scale is true at the equator or at two standard parallels equidistant from the equator. The projection is often used for marine navigation because all straight lines on the map are lines of constant azimuth (true to their bearing).
The Robinson projection is based on tables of coordinates, not mathematical formulas. The projection distorts shape, area, scale, and distance in an attempt to balance the errors of projection properties.
The Mollweide projection, used for world maps, is pseudocylindrical and equal-area. The central meridian is straight. The 90th meridians are circular arcs. Parallels are straight, but unequally spaced.
Sinusoidal equal-area maps have straight parallels at right angles to a central meridian. Other meridians are sinusoidal curves. Scale is true only on the central meridian and the parallels. Often used in countries with a larger north-south than east-west extent
Conical projectionsA conic projection distorts scale and distance except along standard parallels. Areas are proportional and directions are true in limited areas. Used in countries with a larger east-west than north-south extent
Maps are fan shaped. Used for a lot for maps of North America.
Orthographic projections are used for perspective views of hemispheres. Area and shape are distorted. Distances are true along the equator and other parallels.
Are you a global citizen? Taking a “world view “ is about being open-minded and understanding other perspectives and viewpoints on issues that impact us as human beings. Citizens of the planet work towards development that is based on sustainability.
Bibliography http://cagle.slate.msn.com/2000/2000gifs17/cartoon19991114.gif (George Bush & Sept 11) http://www.colorado.edu/geography/gcraft/notes/mapproj/mapprojf.html Daryl Cagle’s Professional Cartoon Index Nov 24/02 In the Global Classroom 2 Graham Pike and David Selby Pippin 2000 A Geopolitical Atlas of the Modern World 1995
5 Essential Map components • Border • Scale • North Arrow/Compass rose • Title • Legend