Leica mojoRTK How-To Manual page 4

Clear Space Between Base and Console
This section is mainly about elevating the base station antenna by placing
the base antenna at the top of a tower. Try to think of the unobstructed
space required between the base antenna and the console antenna as a
large ellipsoid shown below in Figure 1. This space is known as a Fresnel
Zone and there are many more Fresnel zones which wrap around the first
zone, each with a greater radius that the previous zone.
(Visit http://en.wikipedia.org/wiki/Fresnel_zone
Figure 1 – First Fresnel Zone and its obstruction
Figure 1 shows two radio towers communicating with each other in two
situations. The first situation shows no obstruction of the first Fresnel zone
and the second shows some obstruction of the first zone.
Some obstruction of the Fresnel zones can often be tolerated, and as a
rule of thumb the maximum obstruction allowable is 40%, but the
recommended obstruction is 20% or less.
Figure 2 shows two scenarios for using the mojoRTK base station and
console over flat terrain. The first scenario shows the base station set up
on the standard tripod. The second shows the base station antenna at the
top of a tower for increased antenna height.
For more information
www.mojoRTK.com
Page 4/9 Document #1060 rev1.0
for a highly technical explanation)