GPS Phases: Single Epoch Ambiguity and Slip Resolution

  • W. Pachelski
Conference paper
Part of the International Association of Geodesy Symposia book series (IAG SYMPOSIA, volume 115)


An observational equation of the GPS carrier phase contains the pair station — satellite specific and epoch independent bias γ r s = ψ s (t 0)−ψ r (t 0) +N r s , in which N r s is an integer ambiguity and ψ (t 0), ψr(t 0) are transmitter and receiver initial phases. Through sequential processing of phases we update in each epoch, among other unknowns, the γ r s estimates, provided specific minimal configurations of satellites, stations and already processed epochs are satisfied. All second differences of the phases, e.g. with respect to a given reference satellite and reference receiver, ∇Δγ r s =∇ΔN r s , should be then integers on each L1 and L2 band. These conditions can be solved for all N r s ’s (thus implying new γ r s -values) about current estimates of the γ r s ’s as soon as the integer values are found by means of a proper search procedure.

Cycle slips come into view as outliers of observations produced by rapid changes of particular γ r s values. In that case a new observation sequence is created, for which new γ-parameters are estimated, and then consequently constrained for ambiguities.


Ambiguity Resolution Integer Ambiguity Observation Sequence Integer Ambiguity Resolution Single Epoch 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1996

Authors and Affiliations

  • W. Pachelski
    • 1
  1. 1.Space Research CenterWarsawPoland

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