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Figure 32.
Figure 33 shows noise from a nearby personal computer. This signature is typical with a pyramid type response
peaking at channel 100 and the overall noise floor elevated above -120 dBm.
Figure 33.
Figure 34 simulates how RADAR might appear on a site survey. A definite periodic structure can be seen with
peaks and valley repeating every 10 channels (or about every 3.5 seconds since the channels area sampled
once every 0.35 seconds) this repetition is most likely the RADAR antenna rotation rate and will change as the
radar sweep changes. The larger two valleys located at channels 50 and 190 are more a function of the RADAR
PRF (pulse repetition frequency) and pulse width. Actual RADAR interference may look quite different from
this example but the elevated noise floor will cause the ODU to function poorly or not at all. Switching the
suspected RADAR to "standby" will return the noise floor to below -120 dBm if this is the actual cause of the
interference.
62
Iridium Pilot Land Station Installation Guide
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