Google Earth User Guide - Manual (Page 99)

2. Mercator Projection
This process always results in distortion to one or more map properties, such as area, scale, shape, or
direction. Because of this, hundreds of projections have been developed in order to accurately represent a
particular map element or to best suit a particular type of map.
Data sources for maps come in various projections depending upon which characteristic the cartographer
chooses to represent more accurately (at the expense of other characteristics). In the example above, the
Mercator projection preserves the right angles of the latitude and longitudinal lines at the expense of area,
which is distorted at the poles, showing the land masses there to be larger than they actually are.
The following are some common map projections:
Projection DescriptionExample
Albers Equal Area Conic Typically
used for
small
regions or
countries
extending
in an east-
to-west
direction,
but not
continents.
Preserves
angles
between
meridians
and
parallels.
Attempts to
minimize
distortion
for both
shape and
linear
scale, but
neither is
truly
correct.
The
example
here shows
how this
projection
looks over
the entire
earth.