Global Positioning System Reference
In-Depth Information
Projection distortions. (a) Projecting from one plane to another produces no distor-
tions. Here, a shape on the top plane is projected from a point (the star) onto the
lower plane. All that changes is the scale. (b) Now we project from a point, through a
globe (circular arc), and onto a plane (straight line). Distance
AB
equals distance
BC
on the surface of the globe, but the projected image does not preserve distance:
DE
is
not equal to
EF
. (c) If, however, we restrict our projection to globe areas nearest the
plane, distortion is reduced.
