Inertially Aided Lane Recapture after GPS Carrier Lock Loss

  • P. V. W. Loomis
  • G. J. Geier
Conference paper
Part of the International Association of Geodesy Symposia book series (IAG SYMPOSIA, volume 107)


Kinematic surveys and positioning applications based on the Global Positioning System generally require maintenance of carrier lock on four or more GPS satellites for realization of centimeter level accuracies. Frequently, short periods of carrier lock loss for one or more GPS satellites is caused by masking from trees, buildings, and bridges, and radio frequency (rf) interference. If continuous track is not maintained on at least four satellites during the outage, the lane, or integer ambiguity, must be re-established after carrier lock is regained. The use of external sensors, most notably an Inertial Navigation System (INS), can aid in recapture of the integer ambiguity after relatively short periods of loss of lock. Research by Hein et. al. [1] indicates these periods may be on the order of twenty to thirty seconds for high quality inertial systems. This study extends this previous work somewhat to larger lanes and lower quality inertial systems.


Separation Distance Inertial Navigation System Integer Ambiguity Scale Factor Error Sigma Error 
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Copyright information

© Springer-Verlag New York Inc. 1991

Authors and Affiliations

  • P. V. W. Loomis
    • 1
  • G. J. Geier
    • 1
  1. 1.Trimble Navigation LimitedUSA

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