Multipathing – John Deere OMPC20964 User Manual

Page 117

background image

RTK Base Station Setup






A—Good Sources

B—Multipath Sources

Before explaining how to protect against Multipathing,
let’s discuss exactly what Multipathing is: Each satellite
sends down time coded messages for any receiver to
pick up. If a receiver sees multiple time coded
messages from the same satellite, it determines there
is a problem with the satellite and discontinues using
that satellite until it determines the problem is
corrected. This could take up to minutes before the
situation corrects itself. The following are some
examples of what causes multipath.

• Metal roofs

• Center pivots

• Water towers

• Pickup trucks

• Grain bins

• Bodies of water

In the following pictures, we have provided illustrations
to help show how Multipathing occurs. The time coded
signal from the GPS satellite is being beamed down in
all directions, so if the same time coded signal is
reflected off of an object back towards a receiver, the
receiver will see the same message many times. If this
occurs, you could see A/B line jumps while operating
in the field

Continued on next page