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Global Navigation Satellite Systems Report of a Joint Workshop of the National Academy of Engineering and the Chinese Academy of Engineering (2012) / Chapter Skim
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Impact of Intentional, Low Power, In-Band, Personal Privacy Devices (PPDs) on Aviation--A.J. Van Dierendonck
Pages 147-152

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From page 147...
... However, because of diverse location and redundancy of WAAS reference receivers, no interruptions of WAAS operations were noticed. RFI was characterized by analyzing data collected from GPS receivers, spectrum analyzers, and time samples captured by real time data collection (snapshots)
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From page 148...
... There were also addi tional GPS receivers/antennas installed at the GBAS shelter to record more detailed information when severe GBAS degradation was noted -- one antenna with moderate directivity that was pointing horizontal northward along NJT, and one omni-directional pointing up. Of course, received interference power was greatest during the closest approach of the interference source.
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From page 149...
... OBSERVED L1 C/N0 DEGRADATION -- RFI POWER ESTIMATES Figure 3 presents a histogram of Normalized Measurements of C/N 0 (L1 Carrier Power-to-Noise Density ratio) from a WAAS G-II Receiver that VanDierendonck_Fig2.eps 2 bitmaps, landscape FIGURE 2 Typical wideband RFI.
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From page 150...
... The estimated RFI power variation due to other uncertainties is significant -- transmit antenna gain and the loss exiting the vehicle, and the exact location of RFI transmitter (10 to 11 dB)
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From page 151...
... It is highly dependent on the structure of the vehicle and location of the RFI transmitter within the vehicle, which is not easily modeled. GNSS ground RF operating environment requirements may have to be improved by "hardening" from sighting and operational considerations.
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From page 152...
... 152 FIGURE 5 Degradation of normalized C/N0 versus GPS time-of-day (in seconds) at Houston WRS.
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Key Terms

  • navigation satellite
  • global navigation
  • variation due
  • gps receivers
  • interference source

  • severe degradation
  • rfi transmitter
  • spectral peak
  • estimated rfi
  • power variation

  • scenario near
  • reference receivers
  • rfi power
  • gbas reference
  • reference receiver

  • program determined
  • reference station
  • avionics minimum
  • gbas facilities
  • gbas shelter

  • loss uncertainty
  • series demodulation
  • gbas service
  • operational considerations
  • gps time

  • polarization mismatch
  • receiver normalized
  • gnss ground
  • spectrum analyzers
  • diverse location


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