Spatial Reference Manual
Page 52 of 158
Version 4.4
04/06/2019
Spatial is installed in a car and the car drives over a large piece of magnetised steel,
this will be compensated for. Another example is driving through a tunnel which is built
from heavily reinforced concrete. It is important to note that for Spatial's dynamic
magnetic compensation filter to operate correctly, Spatial needs to get a GNSS fix at
least once every time it is moved more than 50km. Each time Spatial moves more
than 50km the new position is stored permanently and allows Spatial to update its
world magnetic model values.
There are three types of magnetic calibration available, these are 2D calibration, 3D
calibration and automatic calibration. 2D calibration involves one level rotation about
the Z axis and is designed for vehicles that cannot easily or safely be turned upside
down, such as full size cars, planes and boats. 3D calibration involves rotating through
all orientations and is designed for vehicles that can easily and safely be rotated
upside down, such as model size vehicles. 3D calibration offers slightly better
performance and is recommended where possible. Automatic magnetic calibration
continuously and automatically calibrates for static magnetic interference while the
unit is in operation. It is not as accurate as the 2D or 3D calibration, however it is very
convenient for applications where Spatial needs to just work without user intervention.
Please note that if Spatial is going to be used in a vehicle, the calibration should be
performed while Spatial is mounted in and fixed to that vehicle. This means that the
whole vehicle must be moved to perform the calibration. The calibration needs to be
performed in an area away from sources of magnetic interference. For example if
Spatial is installed in a car, the calibration should not involve driving over steel drains
or reinforced concrete etc. If Spatial is being calibrated to operate standalone, the
calibration should not be done on a desk with a steel frame.
10.5.1
2D Magnetic Calibration
The following procedure should be used to perform a 2D magnetic calibration.
10.5.1.1
Using the Spatial Manager Software
1. The unit should be powered on while the vehicle is in a level orientation and
kept stationary.
2. After power on wait 5 minutes for the temperature and filter to stabilise.
3. Open Spatial Manager and connect to the device. Ensure that the device has a
GNSS fix before proceeding.
4. In the Tools menu, open Magnetic Calibration. Click the 2D Calibration button.
See section 11.9.2.
5. Whilst keeping as level as possible, rotate the vehicle in either direction through
one and a quarter full rotations. In a car this can be achieved by driving in one
and a quarter circles.
6. Check the status in the Magnetic Calibration window to ensure that the
calibration completed successfully. If not successful click Cancel, wait 2 minutes
and repeat from step 4. Do not press the save button in the lower half of the
dialogue, this will over write the new calibration values. The calibration values
are automatically saved internally.
