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The Global Positioning System A Shared National Asset (1995) / Chapter Skim
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Pages 79-81

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 79...
... . However, the accuracy without SA greatly depends on the condition of the ionosphere at the time of observation and user equipment capabilities.
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From page 80...
... (II/IIA Satellites) 1~" i'-~"~ '""''' ~ "" "- ~'~ ~ ~1~ ''~"~ ~ ~ ~ ~ ~'~'~ i'-I'd ~ ~ ~ ~ ~'~'~ Atmospheric Delay Ionospheric 7.0 7.0 I Tropospheric 1 0.7 1 0.7 Clock and Ephemeris Error | 3.6 | 3.6 Receiver Noise 1.5 1.5 Multipath 1.2 1.2 Total User Equivalent Range Error (WERE)
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From page 81...
... Although these values would intuitively be lower than the 1 nautical mile terminal area protection limit value, availability improves for the 0.3 nautical mile non-precision protection limit because the barometric altimeter inputs provide extra information in this phase of flight. Reduced Data Rate Requirements for DGPS Corrections.
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Key Terms

  • ephemeris error
  • accuracy requirements
  • navigation message
  • receiver noise
  • protection limit

  • nautical mile
  • user equipment
  • horizontal accuracy
  • data rate
  • differential corrections

  • signal tracking
  • typical horizontal
  • sps users
  • horizontal dop
  • pseudorange measurements

  • altimeter inputs
  • limit value
  • aviation applications
  • current level
  • gps receiver

  • mask angle
  • positioning accuracy
  • barometric altimeter
  • range error
  • availability improves

  • accuracy improves
  • mitre corporation
  • dgps corrections
  • satellite range
  • timing accuracy


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