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8 RTK Mapping
8.2.4 Accuracy Considerations
Your RTK system has been designed to achieve centimeter levels of
accuracy. There are a number of important tools incorporated within
the system to help achieve this. However, to ensure ultimate quality, it
is imperative that good data collection procedures are followed.
In considering accuracy requirements, it is important to determine
whether or not the data being collected is to be associated with data
collected by other means. In most instances, the data collected by your
RTK system is required for incorporation into an existing GIS. This
GIS usually stores its current data in terms of a common underlying
coordinate system, such as a national grid or local coordinate system.
The following factors have an effect on ensuring the required levels of
accuracy are obtained:
precision estimates
calibrating to existing control points
geoidmodels
Precision estimates
Your RTK system computes values that provide an estimate of the
quality of the GPS position that is being derived. These values provide
estimates of the precision associated with the location of the phase
center for your roving receiver’s GPS antenna.
You can make valuable use of these precision estimates during your
RTK data collection activities. They can be used when configuring
your roving receiver to indicate precision tolerances (or masks). A
position is not logged if it does not fall within the assigned tolerances.
Separate precision tolerances can be set for the horizontal and vertical
components of the position. Precision tolerances are further split to
enable separate settings to be made for positions collected as a result
of static or roving techniques. Static and roving techniques are
described later in Data Collection, page 197.
192 TSC1 Asset Surveyor Operation Manual