Intel Falcon 8+ User Manual page 69

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accuracy is good, while on the other side position accuracy is extremely poor. If the
UAV moves out of the shadow and more satellite signals can be used to calculate the
position, the UAV can suddenly change its position due to the new calculation.
Therefore the pilot needs to pay special attention in such situations. Whenever there
are potential shadings of the GPS signal, it is recommended to not use GPS-Mode but
to activate Height-Mode on the CTR.
When the Intel Falcon 8+ UAV detects a low GPS quality, it automatically activates
Height-Mode and gives the respective warning
warning). Nevertheless it is strongly recommended to actively switch to Height-Mode
on the CTR beforehand, because it is unpredictable when the system will switch
between flight modes. Additionally the system might only switch to Height-Mode, when
the positional accuracy might already be too low for the current flight situation.
Figure 3-13. GPS multi path effects
When the UAV is placed close to walls which can reflect the satellite signal, the GPS
receiver has no possibility of identifying if the signal comes from a reflection or directly
from a satellite. Therefore there might be situations (often in narrow streets) where
reflections are interpreted incorrectly and full GPS reception is displayed, but the actual
position accuracy is very low. Therefore the pilot needs to pay special attention in such
situations. Whenever there are potential shadings or reflections of the GPS signal, it is
recommended to not use the GPS-Mode.
Compass error estimation
In addition to the compass sensors of the AscTec Falcon 8+, the UAV is equipped with a
compass error estimation algorithm.
The compass error estimation uses, among others, GPS-data to estimate the heading
of the UAV. For this purpose, horizontal flight movements are necessary. The collected
data is used to compensate for potential external disturbances of the compass sensors.
Directly after launching it can take the compass error estimator up to 30 secs to work
properly.
The compass error estimator is active only in GPS-Mode. It is not active in Height-Mode
®
TM
Intel Falcon F8+
GPS lost
User Manual
(see also chapter 3.12.4 GPS
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