Position Gps Antenna Over Base Point; Figure 4.3. Base Antennae Mounted On Conventional And Gps Tripods - ashtech Z-Xtreme System Manual

the base site, it is best to have a clear location to give the RTK system the
most satellites possible to work with.
2. The site should be on a high point in relation to surrounding terrain. This is to
facility the greatest range possible for the base radio transmissions. Line-of-
sight obstructions between the base and rover systems will reduce the
workable distance between the two systems.
If a desired existing control monument does not meet the two considerations above, it
is best to either select a different control point or transfer the position of this point to a
more suitable site by conventional means or through the use of post-processed static
mode of satellite surveying (assuming the site is not too heavily obstructed).

Position GPS Antenna Over Base Point

In most cases, the base receiver antenna will be positioned over a point with known
coordinates. In some cases, the coordinates of the base GPS antenna will be
assumed (computed by the base receiver to an accuracy of approximately 20 meters).
In either case, a physical monument will exist over which the GPS antenna must be
accurately positioned. The two most common mounts for the receiver antenna are a
conventional tripod and a fixed-height GPS tripod (Figure 4.3). Either is sufficient for
the task but the fixed-height tripod is recommended since it eliminates the possibility
of incorrectly determining the instrument height of the antenna.
Figure 4.3. Base Antennae Mounted on Conventional (left) and GPS Tripods (right)
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