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Rapid recovery of precise position after temporary signal loss

  • US 10,422,885 B2
  • Filed: 10/07/2016
  • Issued: 09/24/2019
  • Est. Priority Date: 03/18/2016
  • Status: Active Grant
First Claim
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1. A method for providing or rapidly recovering an estimated position of a mobile receiver, the method comprising execution of the following steps at or by the mobile receiver:

  • receiving a set of one or more carrier satellite signals and a correction signal encoded with correction data that is related to the one or more carrier satellite signals;

    measuring the carrier phase of one or more received satellite signals a first measurement time;

    estimating a wide-lane ambiguity and narrow-lane ambiguity in the measured carrier phase of the one or more received satellite signals for the first measurement time and estimating tropospheric bias for one or more of the carrier satellite signals;

    storing, at regular time intervals for the first measurement time, backup data comprising a set of the following post-convergence or resolved values;

    the estimated wide-lane ambiguities, the estimated narrow-lane ambiguities, the estimated tropospheric delay bias, raw measured carrier phase of the received satellite signals, and corresponding estimated receiver positions;

    detecting a loss of lock on the measured carrier phase associated with loss or lack of reception of one or more of the carrier signals for a loss time period;

    after the detected loss of lock once at least some carrier phase signals are reacquired, measuring the carrier phase of one or more received satellite signals at a second measurement time;

    retrieving or reading the backup data and applying the backup data to a real-time kinematic (RTK) filter to provide a relative position vector between the mobile receiver at the first measurement time and the mobile receiver at the second measurement time and to provide recovery data associated with a satellite-differenced double-difference estimation for the mobile receiver between the first measurement time and the second measurement time;

    applying the relative position vector, the backup data, the recovery data from the RTK filter, and the correction data with precise clock and orbit information on the satellite signals, as inputs, constraints, or both for convergence or resolution of one or more predictive filters on wide-lane and narrow-lane ambiguities in accordance with a precise positioning algorithm;

    estimating a precise position of the mobile receiver based on the resolved narrow-lane ambiguities and wide-lane ambiguities that are in a converged state or fixed state, where the above steps are executable or implemented by a data processor of an electronic data processing system of the mobile receiver;

    wherein the mobile receiver position at the first measurement time comprises a precise point positioning position of the mobile receiver at the first measurement time, and wherein the recovery data includes one or more of the following;

    RTK double-difference (DD) wide-lane integer ambiguity, ∇

    Δ

    NWLij(RTK);

    RTK fixed refraction-corrected (RC) double-difference (DD) ambiguity, ∇

    Δ

    NRCij(RTK); and

    the relative position between the reference receiver and the mobile receiver, and the variance/co-variance of the relative position.

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