Spectra Precision ProMark 800 Reference Manual User Manual

Page 89

RTK Implementation

As a rover user, you should make sure this function is also
activated at the base before activating it in your radio
receiver, otherwise the radio link won't work at all.

If you are using heterogeneous sets of radios (i.e. radio
transmitters and receivers from different manufacturers),
make sure this function is disabled in the radio receiver or
transmitter where it is made available.

• Scrambling: Also made available by some radio

manufacturers. A bit-encoding process intended to
improve the overall performance of the radio transmission
by better balancing the succession of "0's" and "1's" in the
radio transmission channel. This is to avoid some
malfunctioning that might appear when too many “0's” or
“1's” are supposed to be transmitted in a row.

As a rover user, you should make sure this function is also
activated at the base before activating it in your radio
receiver, otherwise the radio link won't work at all.

Activating a Radio Data Link

Some radios are plug-and-play units, some others need a few
preliminary settings (channel number, data rate + internal
port settings).

Pros and Cons

With radios, you are usually independent of any third-party
data provider. Your base can on its own generate and transfer
RTK correction data via the radio. This is possible any time,
from any place. In addition, several rovers can work in RTK
from the same base (multi-point mode).

However, wave propagation in the UHF band is sometimes
difficult. The radio range can dramatically be reduced if
obstructions exist between the base and the rover. As a
general rule, radio antennas should be raised as high as
possible.

Cellular Mobile

Communications

Implementation

Cellular modems or cell phones can be used for the data link
in one of the following two configurations:

• A pair of modems operating in CSD mode. One is used at

the base and the other at the rover. The data link operates
like a phone link, the rover being the caller. This