Data Sheet

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9.1.10. Testing
The ability of a beacon to correctly position itself and determine the submap in
which it is located completely depends on the correct measurement of the
distance to each stationary beacon
Stationary beacons in a submap emit at different frequencies. It is important to
ensure the same reception conditions from different stationary beacons and
frequencies, respectively, because the emission spectrum at one frequency has
limited suppression at a neighboring frequency.
The signals can flow into adjacent frequency channels, this is reflected in the
appearance of false triggers and incorrect determination of the distance, as a
result of incorrect positioning, incorrect jitter detection and, accordingly, incorrect
determination of the submap.
To find the causes of such problems, the dashboard has a digital oscilloscope
mode, it displays the envelope of the received signal and trigger triggers. It is
necessary to verify that the main candidate corresponds to the actual distance
and that there are no other candidates that could interfere with the correct
measurement.
As a rule, false candidates preceding the correct one are a consequence of the
penetration of a different frequency, you can check this by turning on the “only
selected transmitter” option, and only the selected beacon on one frequency will
emit, if the false candidate disappears, then this is penetration of a different
frequency and you need to check whether the restrictions are met described
above.
Another case is re-reflection, when the signal reflected from neighboring objects
and turns out to be higher than the main candidate. As a rule, in this case the
false candidate is further than the main candidate, but it cannot be much further
due to attenuation. In this case, you can use the “Min. over raise for new front”
beacon’s setting.
This parameter prefers the candidate who is closer.
When positioning is done correctly, you need to make sure that the given jitter is
correctly estimated, the stationary beacon emits a signal without delay and with
a delay equal to the jitter code multiplied by granularity, in an oscilloscope this
looks like a shift of the main candidate by jitter.
Map built, tested and ready to use.