NavCom SF-3050 Rev.E - Manual (Page 131)

SF-3050 GNSS Product User Guide
– Rev E
4-105
These radiated emissions can interfere with other
nearby antennas. Multiple GNSS antennas in
close proximity to each other can create multipath
and oscillations between the antennas. These add
to position error or the inability to process the
satellite signals.
 Most antenna‟s have better gain when the satellite
is high in elevation. Expect tracking performance
to fade as the satellite lowers in elevation. It is not
unusual to see 10dB difference in antenna gain
(which translates into signal strength) throughout
the entire elevation tracking path.
 Map obstructions above the horizon using a
compass and inclinometer. Use satellite prediction
software with a recent satellite almanac to assess
the impact on satellite visibility at that location
(available on NavCom‟s web site).
 A clear line of sight between the antenna and the
local INMARSAT satellite is required to track the
StarFire signal. INMARSAT satellites are geo-
synchronized 35,768kms above the Equator,
currently at Longitudes 15.5 West, 97.65 West,
142 West, 025 East, 109 East, and
178 East. An inclination and bearing estimation
tool is available on NavCom‟s website to aid in
determining potential obstructions to StarFire
signal.
GNSS Sensor
Mount the SF-3050 GNSS sensor on a flat surface.
Shock isolators suitable for 0.50kg (1.1 lbs) may be
necessary for environments with high vibration, i.e.,
earth-moving equipment or aircraft.