Blue Mark DroneScout 230 Series, Руководство пользователя

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DroneScout Receiver Manual - version 1.0 May 2022 - © BlueMark Innovations BV 2022
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1.8 Maximum detection range
The maximum detection range depends on several factors:

Effective radiated power (ERP) of the transponder (transmit power, antenna design)

Antenna height
of the receiver and transponder. Detection range increases with higher
height as it converges to free-space propagation.

Antenna gain and directivity of the receiver. The maximum ERP power of the transponder is
limited by the WiFi/Bluetooth technology standard.

Line of sight versus non-line of sight to the transponder due to buildings, trees, hills etc.

Weather
: rain, fog or other “wet” weather will limit the range.

Moving drone : if the drones moves, it will impact negatively on the range. The average RSSI
will vary more (signals may be lost more easy). Also if the drones move fast, typically the drone
will tilt. In such a case, the drone may block partly the signals towards the receiver.

Probability threshold
of detection 1 .
No guarantees can be made about the detection range , due to the complex nature
of wireless propagation, as shortly described above. Typically, the detection range is at
least multiple kilometers.
The detection range below is calculated based on internal measurements, that have been
extrapolated using the “best-case” Free space propagation model
2 .
In general, free-space is considered the most ideal situation. In real-life situation there is more
attenuation between the receiver and beacon. Typically, how higher the receiver is installed, how
more the propagation mimics free-space. Hence, the detection range increases. This is supported
for instance by publications like:
“Characterization of Radio Path Loss in Seaport Environment for
WiMAX Applications” - Ming-Tuo Zhou , Joe Jurianto , Jaya Shankar , M. Fujise 3
The free-space path loss model is:
PL
= 20
10
0
+
Where d is the distance, d
0
, a reference distance and c a constant value that among other depends
on the frequency. If the distance d doubles i.e.
= 2
, the path loss will increase by 6 dB and if d
would be 10 times larger, the path loss increases by 20 dB.
Measurement setup:

receiver antenna height 2.5 m

drone/transponder height 10 m

transponder ERP power 20 dBm.

RSSI measurements based on a
slow
moving drone equipped with the DroneBeacon
transponder.

flat agricultural land

nearby trees > 15 meter (behind antenna), nearby building > 25 meter (behind antenna)

nearby building can act as reflector, so results could be (slightly) too optimistic.

sunny weather
1 The received signal varies both in time and location due to the reception of multiple radio signals (like direct
path and ground wave). In time, typically the average signal strength is used. With respect to locations, paths
can add up constructively or destructively, which depend on the path difference(s). As a result it means that at
distance N there is a variation in received signal strength depending on the location. If you are on the edge of
the detection range, you won’t always detect the transponder due this variation. In this document we use 50%
of the area locations at distance N.
2
https://en.wikipedia.org/wiki/Free-space_path_loss
3 http://ap-s.ei.tuat.ac.jp/isapx/2006/pdf/3B1b-4.pdf (Table 1).