User's Manual

5 Setting up the Receiver
40 SPSx80 Smart GPS Antenna User Guide
Common ways to set up a base station
You can set up a base station in different ways depending on the application, coverage
area, degree of permanence versus mobility, and available infrastructure. Before you set
up a base station, please read Chapter 4, Setup Guidelines.
Setting up a base station for permanent or semi-permanent installation
For construction applications, where machine and site positioning operations using
GPS will be carried out over a long time (weeks, months, or years), ensure that you
choose the base station location carefully.
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. An SPSx50 or SPS770
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.
The GPS antenna most commonly used is the Trimble Zephyr Geodetic
™
Model 2.
This antenna has a large ground plane that eliminates 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. 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.