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Barometric (autocalibrated by GPS):
Barometric altitude will be used,
but the barometer will be automatically calibrated using the altitude data
from the GPS by means of an algorithm that optimizes the final result.
Barometric (autocalibrated by CDEM):
Barometric altitude will be used,
but the barometer will be automatically calibrated using the altitude data of
the 3D relief map (3D relief map must be loaded).
8.12.2.1 Barometer calibration
It is very important to calibrate the barometer in order to achieve reliable data,
TwoNav provides you several ways to calibrate it:
Manually:
If you know the current altitude, enter it.
Current GPS altitude:
Takes the current altitude from the GPS by means
of an algorithm that optimizes the final result.
Current CDEM altitude:
Takes the current altitude from the 3D relief map
(3D relief map must be loaded).
Note:
This option might minimize little errors of altitude data from the GPS. It also
overcomes limitations of the barometric altimeter regarding atmospheric pressure
and temperature, alien to altitude changes.
8.12.3 Bearing (Compass)
Bearing data determines the orientation of the map when the function
‘Orient
map: Track
up’
is enabled. TwoNav offers you different ways to determine the
bearing you are taking during your navigations:
GPS:
The latest positions received are used to calculate the bearing of
your current movements. As soon as you stop, this reference will not be
reliable, as there will be no reliable movements to calculate the bearing.
Compass:
Data recorded from the compass will be used in order to
determine the orientation of the device.
Automatic (recommended)
:
Driving slowly:
Data recorded from the compass will be used.
Driving fast:
Data recorded from the GPS position will be used.
8.12.3.1 Compass calibration
The calibration of the electronic compass is essential in order to display right
directions during your navigations: Rotate the device slowly and continually on a
horizontal position for a few seconds until compass is calibrated.