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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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A Global Safety of Life Service from Multiple GNSS Constellations--Per Enge
Pages 95-104

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From page 95...
... INTRODUCTION Satellite navigation serves a wide breadth of applications based on the satellites depicted in Figure 1. As shown, the vast majority of these satellites are in medium Earth orbit (MEO)
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From page 96...
... Other applications include ship navigation, pointing information for space craft, land survey, energy exploration; and time transfer for telecommunications, power delivery, and financial transactions. Attracted by this utility, Russia is rejuvenating its satellite navigation system, called GLONASS.
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From page 97...
... L2 is 1227.60 MHz and also carries a civil signal with a 1 Mcps chipping rate on the seven most recent GPS satellites. Taken together, L1 and L2 provide redundancy to combat accidental RFI and a means to remove the dispersive delay due to the ionosphere.
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From page 98...
... Reprinted with permission. Enge_Fig3.eps bitmap, landscape
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From page 99...
... How ever, they share the main features: triple frequency diversity with at least two signals in ARNS bands surrounding L1 and L5. IMPACT ON CIVIL AVIATION AND SAFETY OF LIFE APPLICATIONS Civil aviation has augmented GPS to detect faults or rare normal condi tions that threaten flight safety.
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From page 100...
... After all, geometric diversity means that the navigation solutions will be over-specified and that the subset geometries will be stronger. The air navigation community is researching this possibility and has developed a concept imaginatively known as advanced RAIM or ARAIM.
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From page 101...
... Aviation and safety-of-life applications would welcome this robustness. RADIO FREQUENCY INTERFERENCE As mentioned earlier, GPS satellites broadcast from MEO, and so the satel lites are approximately 12,000 miles above the receivers.
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From page 102...
... The GBAS antennas were placed next to the New Jersey Turnpike, and the ground receivers suffered frequent continuity breaks during the test period. These breaks were due to PPDs carried by vehicles on the New Jersey Turnpike.
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From page 103...
... Moreover, the pressure to find new radio spectrum for worldwide Internet access will endanger the weak GNSS signals coming from medium Earth orbit.
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From page 104...
... 104 GLOBAL NAVIGATION SATELLITE SYSTEMS REFERENCE van Diggelen, F
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Key Terms

  • navigation satellite
  • satellite navigation
  • gps receivers
  • civil aviation
  • gps satellites

  • frequency diversity
  • medium earth
  • earth orbit
  • gps signal
  • life applications

  • radio frequency
  • provide geometric
  • geometric diversity
  • van diggelen
  • chipping rate

  • rare normal
  • frequency interference
  • radio navigation
  • civil users
  • navigation aids

  • civil signal
  • triple frequency
  • augmented gps
  • measuring equipment
  • normal conditions

  • aviation community
  • time transfer
  • power delivery
  • top trace
  • jersey turnpike


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