Iridium Pilot Installation Manual page 65

If RADAR presents a problem for Iridium Pilot it will most likely be an out of band type interference. Given the
RADAR antenna spends most of the time facing away from the ADE the noise floor may display a cyclic pattern
of raised and normal amplitude causing something like every third channel to be elevated. Since the scan
rate of the SST and the sweep rate of the RADAR are not synchronous the affected channels may "walk" across
the display from sweep to sweep causing the noise floor of a long duration scan (> 10 scans) to elevate nearly
uniformly.
Peak values of normal Iridium signals are typically -90dBm or below. Peaks in excess of -85 dBm should be
suspected as terrestrial interferers and be tracked down.
At the conclusion of the survey the user should stop the tool and then select the file menu button and save the
file using the default naming convention which contains the IMEI of the unit under test along with a time date
stamp. The data is stored as a comma separated value (CSV) and can be sent to a tier 2 or tier 3 organization
for further assistance in analysis. Tier 1 is end user support from the (SP) service provider. Tier 2 is SP support from
Iridium. Tier 3 is engineering support to Tier 2.
The tool has additional configuration parameters to allow the user to scan smaller portions of the band using
the slider just below the command bar. This can be useful in focusing the display on say 10 channels of interest
around a suspected interferer and collecting multiple short scans in 1/25th the time of a full scan.
Figure 23.
Examples of "Bad" Site Survey Plots
The following three examples simulate interference of the ADE receiver and are examples of bad installation
locations. This first example shows interference from a high power HF radio near the ADE. The transmitter was
keyed for part of a 90 second scan (starting at ch 177 and ending on the subsequent scan at ch 88) and shows
the current mean noise floor rising above the -120 dBm limit across the band (broadband noise). Additionally
antenna 7 can be seen to 20 to 30 dB of excess noise meaning high elevation passes would be blocked.
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Iridium Pilot™ Installation Guide
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