## Projection/Datum Shift Sequence

Coordinate manipulations involve the steps above. If you are only
interested in geographic coordinates, you do not need to use the forwad and
inverse projection equations.

To go back from datum 2 to datum 1, you repeat the same steps and exchange
the datum 1/2 on the two sides of datum transformation.

On the fly projections of data sets with different datums or projections must
use this process to display points on the screen, or to go from the mouse
position to the coordinates.

To plot the UTM grid on a Lambert Conformal Conic projection map, you must
first convert to geographic, and then use the equations of the other projection.

last revision 11/28/2018