Eagle Tree Vector - Manual (Page 27)

USER GUIDE
27
4.2 Mounting the GPS/MAG Sensor
4.2.1 GPS Signal Interference
RF noise from video transmitters, cameras, and other devices can interfere with GPS reception. It’s important
to mount the GPS/MAG as far away from these sources as practical.
Also, obstructions such as trees or buildings that block the Vector from having a clear, unobstructed view of the
sky can cause issues with GPS reception.
If the GPS loses signal during GPS flight modes, such as RTH or loiter, the Vector will exit these flight
modes.
GPS satellites are constantly moving around in the sky, and GPS signals are affected by changes in
weather, so GPS fix quality can vary greatly over time, even at the same location.
4.2.2 Magnetometer Interference
Power lines generate electromagnetic fields when current flows through them. These magnetic fields will
interfere with the compass function of the GPS if insufficient separation is observed. Unless you don’t plan to
use the compass (it’s required for multirotor GPS modes and optional for fixed wing GPS modes) you must
mount the GPS/MAG at least 8cm (3.5”) away in all directions from any high current carrying wires, such as
your battery wires, ESC wires, or motor wires. Additionally, magnets (such as motor magnets or canopy
magnets) can interfere with the compass, and the GPS/MAG should be mounted as far away from them as is
feasible.
If the compass is enabled, and there is electromagnetic interference, GPS flight modes such as RTH and
loiter will not work correctly, and the model may fly erratically when in these modes! Multirotor
models could “toilet bowl” and the model may fly the wrong direction in RTH!
4.2.3 GPS/MAG Mounting Orientation
The GPS must be mounted so that the top of the GPS (the label) normally faces
toward the sky.
If you are going to use the compass, the GPS/MAG must be mounted flat and level,
and facing forward. The GPS/MAG cannot be tilted or rotated relative to the
Vector. The arrow on the GPS/MAG must be pointing in the same direction as the
Vector arrow.
If the compass is enabled, and the GPS/MAG is not mounted in the correct orientation or detaches from
its mounting during flight, flight modes such as RTH and loiter will not work correctly, and the model
may fly away at high speed when in these modes! Multirotor models could “toilet bowl” and the model may
fly the wrong direction at high speed during RTH!
The GPS/MAG must be flat relative to the Vector. Mounting errors of even a few degrees in the pitch or
roll axes can introduce noticeable error in the compass heading, leading to toilet bowl behavior in multirotors
or inaccurate navigation in planes.
The Vector automatically computes the magnetic declination (compass error) at your location, so it is
normally not necessary to rotate the GPS/MAG to correct for compass error.
The GPS/MAG has an LED, which can be viewed from the back of the unit (see the arrow on the label).
When the LED is OFF (not blinking) the GPS/MAG has attained a 3D GPS Fix.