Ellipse
– Operating Handbook
ELLIPSEOHAIR
Magnetic calibration in airborne applications
When magnetometers are used as heading reference, a
magnetic calibration is mandatory for
normal sensor operation
. Different calibration methods are provided, depending on accuracy or
ease of use requirement.
Light UAV calibration
As long as a UAV (fixed or rotary wings) is light enough to be held by a few persons, a 3D
calibration, made on the ground is to be preferred. The basic procedure is the following:
1.
Install the sensor as described in previous sections, and place the whole system away
from external magnetic disturbances (buildings, other vehicles, etc)
2.
Press “Start acquisition” button on sbgCenter calibration window
3.
Rotate the system as much as possible. The main point is to cover the whole flight
profile, but a larger amount of points, beyond the flight profile will provide even
better results.
4.
Press “Calibrate” and check calibration results. Press “OK” to finalize the calibration
procedure.
5.
Power cycle the sensor if you need immediate operation after calibration.
Airplanes, helicopter and large UAV applications
In flight 3D calibration
This calibration will give the best results as it allows to map the magnetic field in real 3D so
that magnetometers readings are kept consistent even during turns and pitching.
In order to perform the calibration procedure, user can use the integrated sbgCenter calibration
tool, or a data-logger to store the “magnetic calibration data” outputted by the Ellipse during
calibration procedure.
Procedure
Once the aircraft is in steady flight at a reasonable altitude, the goal is to cover different
orientations which are representative of the flight domain of the aircraft.
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