User's Manual

5 Setting up the Receiver
42 SPSx80 and SPSx81 Smart GPS Antennas User Guide
A semi-permanent or permanent base station helps to eliminate the types of error that
can result from repeated daily setups, and ensures that you always use the GPS
antenna at the exact original location. The requirement for a permanent base station
setup increases as more receivers that use the base station as a source of corrections,
increases the cost of any base station downtime.
On the largest jobsites, and on those that remain operational for the longest time, a
permanent or semi-permanent installation is a popular solution. A modular GPS
receiver is typically used as the base station, located in a site office or trailer where it is
easy to access (to check or configure), and where it is secure from theft and the
weather. The GPS and radio antennas are normally mounted on a permanent structure
on the roof of the building, where they are high and clear from obstructions and where
the radio antenna can provide the maximum range of operation.
Trimble recommends that you use the Trimble Zephyr Geodetic
™
Model 2 GPS
antenna. This antenna has a large ground plane that reduces multipath, providing the
best GPS performance at the base location. The antennas are connected to the receiver
by high quality RF cables.
The receiver is connected to a permanent power supply (mains or generator power).
The internal battery of the receiver is always being charged, and acts as an
uninterruptible power supply if there is a power failure. In some cases, the receiver may
also be connected by an Ethernet cable to the Internet, so that it can be monitored and
configured from a remote location, and can warn an administrator by e-mail or text
message if there is a change to the configuration or status. In these situations, the
receiver can transmit GPS RTK corrections to a remote radio or receiver over the
Internet, for rebroadcast requirements, without using repeaters.