Projection Hemisphere

There are two different Hemisphere options:

• Lower Hemisphere
• Upper Hemisphere

Lower Hemisphere

In the Projections pane, the default projection is a Lower Hemisphere projection. For a horizontal stereonet projection, this means that the plot represents the traces of planes and poles on the lower half of the sphere, as viewed from above.

Upper Hemisphere

An Upper Hemisphere projection can also be used. This displays the traces of planes and poles on the upper half of the sphere when viewed from above. An Upper hemisphere plot is therefore equivalent to a Lower hemisphere plot rotated by 180 degrees. Use whichever plot you prefer, but be consistent, or confusion will result.