1
Geodetic Models and Projections

2
Geodesy
Geodesy
—
also known as
geodetics, geodetic engineering or
geodetics engineering
—
a branch
of applied mathematics and earth
sciences, is the scientific discipline
that deals with the measurement
and representation of the Earth (or
any planet), including its
gravitational field, in a three-
dimensional time-varying space
(wiki).

3
The Earth
•
Is usually considered to be a sphere and
this is OK
•
The earth’s surface area is approximately
equal to that of a sphere having a radius of
about 6370 km.