Multi-level/multi-threshold/multi-persistency GPS/GNSS atomic clock monitoring
First Claim
1. A method, comprising:
- establishing a measured difference of at least one of a phase or a frequency between an atomic frequency standard (AFS) and a monitoring device;
modeling an estimated difference model associated with the at least one of the phase or the frequency between the AFS and the monitoring device;
computing a residual signal based on the measured difference and the estimated difference model;
analyzing, by a first detector, the residual signal at multiple thresholds, each of the thresholds having a corresponding persistency defining a number of times a threshold is exceeded before one or more of a phase jump, a rate jump, or an acceleration error is indicated; and
analyzing, by a second detector, a parameter of the estimated difference model at multiple thresholds, each of the thresholds having a corresponding persistency defining the number of times a drift threshold is exceeded before a drift is indicated.
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Accused Products
Abstract
Methods and apparatus to monitor GPS/GNSS atomic clocks are disclosed. An example method includes establishing a measured difference between an atomic frequency standard (AFS) and a monitoring device. The method also includes modeling an estimated difference model between the AFS and the monitoring device, and computing a residual signal based on the measured difference and the estimated difference model. In addition, the method includes analyzing, by a first detector, the residual signal at multiple thresholds, each of the thresholds having a corresponding persistency defining the number of times a threshold is exceeded before one or more of a phase jump, a rate jump, or an acceleration error is indicated. Furthermore, the method includes analyzing, by a second detector, a parameter of the estimated difference model at multiple thresholds, each of the thresholds having a corresponding persistency defining the number of times a drift threshold is exceeded before a drift is indicated.
5 Citations
20 Claims
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1. A method, comprising:
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establishing a measured difference of at least one of a phase or a frequency between an atomic frequency standard (AFS) and a monitoring device; modeling an estimated difference model associated with the at least one of the phase or the frequency between the AFS and the monitoring device; computing a residual signal based on the measured difference and the estimated difference model; analyzing, by a first detector, the residual signal at multiple thresholds, each of the thresholds having a corresponding persistency defining a number of times a threshold is exceeded before one or more of a phase jump, a rate jump, or an acceleration error is indicated; and analyzing, by a second detector, a parameter of the estimated difference model at multiple thresholds, each of the thresholds having a corresponding persistency defining the number of times a drift threshold is exceeded before a drift is indicated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus, comprising:
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a meter to measure a difference of at least one of a phase or a frequency between an atomic frequency standard (AFS) and a monitoring device; an estimator to model an estimated difference of the at least one of the phase or the frequency between the AFS and the monitoring device; an analyzer to compute a residual signal based on the measured difference and the estimated difference; a first detector to analyze the residual signal at multiple thresholds, each of the thresholds having a corresponding persistency defining a number of times a threshold is exceeded before one or more of a phase jump, a rate jump, or an acceleration error is indicated; and a second detector to analyze a parameter of the estimated difference at multiple thresholds, each of the thresholds having a corresponding persistency defining the number of times a drift threshold is exceeded before a drift is indicated. - View Dependent Claims (12, 13, 14, 15)
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16. A method, comprising:
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establishing a measured difference of at least one of a phase or a frequency between an atomic frequency standard (AFS) and a monitoring device; modeling an estimated difference model associated with the at least one of the phase or the frequency between the AFS and the monitoring device; and detecting, by a detector, a drift if a parameter of the estimated difference model exceeds a threshold at a corresponding persistency defining a number of times that a drift threshold is exceeded before a drift is indicated. - View Dependent Claims (17, 18, 19, 20)
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Specification