ZED-F9T - Integration Manual
position at very low speed. The output of the low-speed course over ground filter is published in the
UBX-NAV-PVT message (
headMot
field), UBX-NAV-VELNED message (
heading
field), NMEA-RMC
message (
cog
field) and NMEA-VTG message (
cogt
field). If the low-speed course over ground filter
is not activated or inactive, then the course over ground is computed as described in section freezing
the course over ground.
3.1.7.4 Static hold
Static hold mode allows the navigation algorithms to decrease the noise in the position output when
the velocity is below a pre-defined "Static Hold Threshold". This reduces the position wander caused
by environmental factors such as multi-path and improves position accuracy especially in stationary
applications. By default, static hold mode is disabled.
If the speed drops below the defined "Static Hold Threshold", the static hold mode will be activated.
Once static hold mode has been entered, the position output is kept static and the velocity is set to
zero until there is evidence of movement again. Such evidence can be velocity, acceleration, changes
of the valid flag (e.g. position accuracy estimate exceeding the Position Accuracy Mask, see also
section Navigation Output Filters), position displacement, etc.
The CFG-MOT-GNSSDIST_THRS, configuration item additionally allows for configuration of
distance threshold. If the estimated position is farther away from the static hold position than this
threshold, static mode will be quit. The CFG-MOT-GNSSSPEED_THRS configuration item allows you
to set a speed that the static hold will release.
Figure 2: Position publication in static hold mode
UBX-19005590 - R01
3 Receiver functionality
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