Hemisphere GPS V104n User Manual page 32

Table 3-1: Sensor operation summary
Feature Normal Operation
Heading GPS
Pitch GPS
Roll Inertial sensor
Tilt Aiding
The V104n's accelerometers (internal tilt sensors) are factory-calibrated and
enabled by default. This allows for a steady heading solution beyond the
volume associated with just a fixed antenna separation. This is because the
V104n knows the approximate inclination of the secondary antenna with
respect to the primary antenna. The search space defined by the tilt sensor
will be reduced to a horizontal ring on the sphere's surface by reducing the
search volume. This considerably decreases startup and reacquisition times
(see Figure 3-1).
Tilt angle
Gyro Aiding
The V104n's internal gyro offers several benefits. It reduces the sensor
volume to shorten reacquisition times when a GPS heading is lost because
the satellite signals were blocked. The gyro provides a relative change in
angle since the last computed heading, and, when used in conjunction with
Coasting (no GPS)
Gyro
Inertial sensor
Inertial sensor
Figure 3-1: V104n's tilt aiding
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V104n GPS Compass User Guide