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Figure 18: Recommended Second Antenna Placement
The standard antennas supplied in the Boreas Evaluation Kit are the VeroStar VSP6337L. They are an
L1/L2/L5 RTK antenna that support GPS, GLONASS, BeiDou, Galileo, and SBAS. They are environmentally
sealed to the IP69k standard.
If you are sourcing your own antennas, note the following antenna guidelines:
l
The antenna should be capable of receiving both L1 and L2. Heading performance will be significantly
degraded with an L1-only antenna.
l
Active antennas should have sufficient LNA gain, which when accounting for cable losses, provides at
least 33 dB of gain at the connector of the unit.
l
The antenna needs to have an accurate phase centre to be RTK capable. This is also required for the
dual antenna heading to function correctly. Low performance (low cost) antennas are typically not able to
achieve good heading performance.
l
The antenna should support GPS, GLONASS, BeiDou, and Galileo.
l
The antenna should be environmentally sealed, including connectors.
7.8.1 Antenna Cables
The antenna cables should be routed away from powerful RF emitters, high current wiring, high temperatures
and any rotating or reciprocating machinery. It is very important not to bend the antenna cable tighter than its
minimum bend radius, or to allow it to be dented. It is recommended to use wide cable ties, loosely fixed in order
to avoid damaging the insulation or shielding. The cables should not be coiled. Advanced Navigation
recommends:
l
Keeping the antenna cables the same length, and as short as possible.
l
Using either RG58 low loss or LMR240 coaxial cable combined with high quality connectors. LMR300
and LMR400 can also be used to minimise loss for very long antenna cables.
Cable Type
Minimum Bend Radius
Signal Loss
RG-58/U Low Loss
20 mm
~0.92 dB/m
LMR240
20 mm
~0.33 dB/m
LMR300
22.2 mm
~0.26 dB/m
LMR400
25.4 mm
~0.17 dB/m
Table 22: GNSS antenna co-axial cable properties
The Boreas end of the antenna cables must have standard male TNC connectors.
If you are sourcing your own antenna cables it is important to ensure that the antenna has enough gain to
support the signal loss over the cable. Boreas requires a minimum of 33 dB of gain at the connector. With the
standard 4 metre RG-58A/U antenna cables supplied by Advanced Navigation, the minimum antenna gain
required is 36.5 dB.
7.8.2 Antenna Suction Cup Mount
A suction cup mount can be used when antennas need to be mounted at any angle or on a smooth, non-porous
surface such as a window or on vehicles with aluminium or fibreglass bodies. A suction cup mount can be
attached and removed quickly and can easily be moved from one location to another. See
.
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11 Oct 2022
Boreas Reference Manual • Installing Boreas