6 - D2O FL1 Product Manual
3.1 ANTENNA BASICS
Before deciding on a location to install your D2O unit it is important to
understand how the D2O operates.
The D2O uses electromagnetic radio waves to communicate with the
individual satellites in a nano-satellite constellation. Transmission and
reception of these waves is facilitated by the D2O’s antennas.
The D2O knows when these orbiting satellites will be transiting through a
visible section of sky and transmits messages during this window.
The vertical orientation of the D2O’s antennas means that it has the strongest
transmission and reception abilities in a range perpendicular to the Antenna,
emanating in a radial pattern. When a satellite passes through the sky
between the horizon, and up to approximately 75° from the horizon the
D2O has the greatest opportunity for a successful transmission or reception.
Satellite passes below 20° above the horizon have a lower probability of
transmission.
Directly above the Antenna, between 75° and 90° (straight upward), the
transmission and reception abilities of the Antenna are poor.
EFF
ECT
IVE
TR
AN
SM
ISS
IO
N R
AN
GE
90°
75°
60°
45°
30°
15°
0°
75°
60°
45°
30°
15°
0°
0 dBi
-6 dBi
-12 dBi
-18 dBi
EF
FE
CT
IV
E T
RA
NS
M
ISS
IO
N R
AN
GE
HORIZON
HORIZON
SIGNAL STRENGTH
+
-
Most satellite passes will occur across a partial section of sky. This is due to
the orbital pattern of the satellites and their relationship to the D2O’s position
on earth.
Having a clear line of sight to as much of the sky as possible, and in all
directions, will minimise the risk of missed transmission opportunities.
The Antenna gain pattern. The signal strength of the antenna is indicated by the dark arced sections and results in an effective transmission
window of approximately 75° from the horizon.
