ashtech GG Surveyor, Reference Manual

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Differential and RTK Operations 57
Differential and RTK
Ashtech remote receivers (both Differential and RTK) operate with any base station
that generates the industry standard RTCM messages.
Base Data Latency
Both Differential and RTK operation are better the lower the latency of the Base-
Remote data link. To minimize latency set the baud rate of the radios as high as
possible, and use radios that are optimized for low latency GPS operation, such as the
Ashtech SSRadio.
The actual Base-Remote data latency is given in the GGA message (whether in
Differential or RTK modes).
Maximum acceptable base-remote data latency is controlled by $PASHS,RTC,MAX
for both Differential and RTK modes.
Figure 5.1: Combined Differential/RTK Base Station and Remote Operation