What is a map? A representation of the 3-dimensional (3-D) Earth on a 2-dimensional (2-D) (flat) surface
What is a map projection? The process of transforming positions on the Earth's spherical surface to a flat map while maintaining spatial relationships
Distortion Every map projection distorts at least three, and sometimes all four, of the following properties: area (size) shape distance direction Maps covering large areas have much distortion while maps covering very small areas will have negligible distortion
Conic Projection – a map projection that is made by moving the surface features of the globe onto a cone.
Conic Projections the Earth is projected onto a cone, which is then cut lengthwise and laid flat. true along some parallel (line of latitude) somewhere between the equator and a pole and distortion increases away from this standard
Cylindrical projection – a map projection that is made by moving the surface features of the globe onto a cylinder.
Cylindrical Projections the Earth is projected on to a cylinder which is also cut lengthwise and laid flat. true at the equator and distortion increases toward the poles
Azimuthal Projection – a map projection that is made by moving the surface features of the globe onto a plane.
Planar Projections a portion of the Earth's surface is transformed from a perspective point to a flat surface. true only at their center point, but generally distortion is worst at the edge of the map
Equal-Area projections An equal-area projection can be made by using cylindrical, conic, or, azimuthal projections Shapes are distorted but the scale is constant