Ron Hatch NavCom Technology, Inc'

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Ron HatchNavCom Technology, Inc.
New L2C Signal Benefits

• 10 March 2004

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Technical Benefits

• Very significant signal-to-noise improvement over
  the semi-codeless current civilian access to L2
  signal. (gt17dB improvement)
• The data-free segment allows the use of a
  phase-locked-loop for carrier-phase tracking.
  This greatly improves the cycle-slip threshold.
  (Our simulations show that with oscillator
  tracking logic, phase tracking with C/N0 less
  than 20 dB can be maintained)

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Technical Benefits (2)

• Longer codes on both L2CM and L2CL provide a
  significant improvement in the cross-correlation
  (and auto-correlation) properties. This gives a
  very significant improvement in acquisition
  reliability especially in the presence of weak or
  partially blocked signals
• Assuming L2CM will be changed to a new ephemeris
  message with a convolution code, a significant
  improvement in the data message will be attained.

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Practical Benefits

• Both in agriculture and in marine
  applicationsbetter performance in marginal
  situations.
• The StarFire Global DGPS uses the equivalent of
  floating ambiguity carrier-phase navigation,
  thereby achieving ten cm. navigationbut it can
  often take as long as ½ hour to converge to this
  accuracy. Therefore, dropping below four
  satellites can cause this process to start all
  over.
• Measurements from more satellites will remain
  available This can mean the difference between
  usable GPS and unusable GPS.
• Reacquisition of obscured satellites will occur
  more quickly.

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Shading Area A
Shading Area B
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Positioning Next to a Drill Rig
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Conclusion

• NavCom is designing the next-generation GPS to
  take advantage of the new L2C signals. We believe
  that the new signal will be of significant
  benefit to our existing customersparticularly in
  situations where the current system is only
  marginally available.