Iridium Pilot TPIM1301, Руководство по установке

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2: INST
ALLA
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Iridium Pilot Land Station Installation Guide
X-band (~ 3 cm / 10 GHz) and C-band (4-8GHz) radars
Radar Power Min distance at 15˚ vertical separation Min distance at 60˚ vertical separation
0 – 10kW 0.8 m (2.6 ft.) 0.4 m (1.3 ft.)
30kW 2.4 m (7.9 ft.) 1.2 m (3.9 ft.)
50kW 4.0 m (13.1 ft.) 2.0 m (6.6 ft.)
Important
A vertical separation of at least 15° is required from any RADAR to ensure the ODU is out of the main transmit
beam. If this is violated there is the potential the RADAR pulse will damage the sensitive RF receivers in the
ODU or at a minimum disrupt communications each time the RADAR sweeps past the ODU.
Important! A vertical separation of 15˚ is always required from any radar.
Offset Distances from other Communications & Navigation Equipment ODU Location Priorities
This next step will use the Iridium Pilot Land Station equipment to measure the RF environment at the
potential ODU mounting locations prior to permanent installation. This is an important step that will eliminate
the possibility of needing to move the equipment later. It is imperative all RADARs, communications and
navigation systems are ON and operating during this test to ensure all potential interferes are detected.
1. Locate the RADARs. They are usually the highest mounted items near the desired location of the ODU. Look
for locations that are at least 15° below the RADARs and honor the separation distances.
2. Locate Inmarsat radomes and honor the 10 meter separation distances. The Inmarsat and Iridium operating
frequencies are close together and interference is likely if the equipment is too close to each other. If one
system is designated a “backup” then there may be some latitude to violate the offset distance.
3. Locate the GPS antenna. GPS and Iridium frequencies are close together and transmission from the ODU can
affect navigation if the offset distances are not honored.
4. Note metal (RF reflective) surfaces just below the potential ODU location (Figure 7). Any metal in this area
has the potential to reflect RF energy and cause multipath fading.
5. Look at possible locations and the remaining antennae in the immediate area and select the locations with
the fewest potential interferers.
6. Finally look at the obstructions and determine if the site will provide a reasonably unobstructed view of the
sky. Try not to allow any single obstruction to attenuate signal path more than 2 dB.
System Minimum Separation
VHF 5.0 m (16.4 ft.)
HF (ssb) 5.0 m (16.4 ft.)
Inmarsat 10.0 m (32.8 ft.) minimum. Inmarsat may interfere
with Iridium at distances up to 60.0 m (196.8 ft.)
depending on the relative position of the satellites.
Other Iridium antennas (unity gain) 2.0 m (6.6 ft.)
Another Iridium Pilot Land Station Terminal 6.0 m (19.7 ft.)
GPS 10.0 m (32.8 ft.) if it is in the same horizontal plane as
the ODU
Compass 1.0 m (3.3 ft.) estimate