Hemisphere GPS Crescent V100 Series, User Manual

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2: Crescent V100 Operation
Both sensors act to reduce the RTK search volume which improves
heading startup and reacquisition times, and also has the benefit of
improving the reliability and accuracy of selecting the correct
heading solution by eliminating other possible, erroneous solutions.
Hemisphere GPS’ GPS Technical Reference manual describes the
commands and methodology required to recalibrate, query or
change the status of these sensors.
Tilt Aiding
The Crescent V100’s internal tilt sensor (accelerometer) is enabled
by default, is factory calibrated, and constrains the RTK heading
solution beyond the volume associated with just a fixed antenna
separation, since the Crescent V100 knows the approximate
inclination of the secondary antenna with respect to the primary.
The search space defined by the tilt sensor will be reduced to a
horizontal ring on the surface of the sphere. By reducing the search
volume this considerably decreases startup and reacquisition
times. (See figure 2-2.)
Figure 2-2. Crescent V100’s tilt aiding
Tilt
Angle