NavCom SF-3050 Rev.I - Manual (Page 117)

SF-3050 GNSS Product User Guide – Rev I
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Basics of RTK Surveying
RTK (Real-Time Kinematic) is a GNSS system that yields very accurate 3D position fixes
immediately in real-time.
A reference station (base station) transmits its GNSS position to roving receivers as the
base receiver generates them. The roving receivers use the reference station readings to
differentially correct their own positions. Accuracies of a few centimeters in all three
dimensions are possible. RTK requires multi-frequency GNSS receivers and high speed
radio modems.
Proper setup of a reference station minimizes GNSS errors in the rover. The reference
GNSS sensor is set up at a known surveyed location. With this position locked in, it
transmits its code, clock, and reference station coordinate information to the roving
sensor(s). The roving sensor(s) uses this information to correct each GNSS
measurement it receives.
The SF-3050S, when configured as a reference station, can transmit corrections to any
number of roving receivers capable of picking up the radio signal and decoding one of
these correction formats: NavCom proprietary, RTCM 2.3/3.1 for Network RTK
1
, CMR, or
CMR+. The signal can be received in less than ideal environments, though some data
loss may occur.
Setup of the reference station sensor above the roving sensors is recommended to
enable transmission to all rovers in all directions with minimal obstruction. High frequency
radio signals generally travel a shorter distance than lower frequency signals, and do not
penetrate obstructions as well over distance. Figure 110 and Figure 111 illustrate proper
and improper RTK reference station installation.
1 Network RTK is not supported in software version 1.0. The Network RTK software option allows the receiver to
generate and receive RTCM 1000-series messages. The navigation algorithms are designed to support single-base
correction configurations. Network adjusted RTK formats are not currently supported.