Magnetics
Certus contains magnetometers which it can use to measure the Earth's magnetic field in order to determine its heading. The principle is the same as that of a compass. When operating Certus with magnetic heading enabled, sources of magnetic interference can degrade the Certus solution if not compensated for.
Note: Magnetic interference affects the performance of gyroscopes by causing rotation errors; it is recommended that you mount Certus away from magnetic interference.
There are two types of magnetic interference: Static and Dynamic.
Sources of static magnetic interference are predominantly ferrous materials (e.g. steel, iron, nickel, cobalt), high-current cables and permanent magnets located near the Certus. Static disturbances are easily compensated for by running a magnetic calibration. A magnetic calibration should always be performed after installation into a vehicle if accurate magnetometer heading is required. See Magnetic Calibration for instructions on how to calibrate your device.
Dynamic magnetic interference is a much more complex and problematic issue due to its many variable factors and unpredictability. Sources of dynamic magnetic interference include high current wiring, electric motors, servos, solenoids and nearby large masses of metal that don't move with Certus. Certus should be mounted as far as possible from these interference sources.
Certus contains a special algorithm to reduce the effects of dynamic magnetic interference. This is able to compensate for most typical interference sources encountered, however certain types of prolonged dynamic interference cannot be compensated for. The best way to check for dynamic magnetic interference is to use the Raw Sensors view in
If dynamic magnetic interference is causing performance problems and there is no way to mount Certus away or, where practical, magnetically shield it from these interference sources, the magnetometers should be disabled and an alternative heading source should be used, see Disabling Magnetometers.