Phase step alert signal for GPS integrity monitoring
AssigneeLockheed Martin Corporation
InventorRonald H. Clark
Life of this patent
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Abstract
Alerting a user of an integrity error in a global positioning system (GPS) signal transmitted from a transmitter in a global positioning system (GPS) satellite, by detecting an error in the global positioning system (GPS) signal, alerting the user of the error by shifting a phase of the global positioning system (GPS) signal from an initial value by a predetermined phase-shift amount, and returning, in the case that the detected error is corrected, the phase of the global positioning system (GPS) signal to the initial value. Preferably, the GPS signal is phase-shifted by the predetermined phase-shift amount using an alert timing pattern which indicates the level of detected error.
Claims16
A method for alerting a user of an integrity error in a global positioning system (GPS) signal transmitted from a transmitter in a global positioning system (GPS) satellite, the method comprising the steps of:
- detecting an error in the global positioning system (GPS) signal;
- alerting the user of the error by shifting a phase of the global positioning system (GPS) signal from an initial value by a predetermined phase-shift amount;
- and
- returning, in the case that the detected error is corrected, the phase of the global positioning system (GPS) signal to the initial value.
A method for alerting a user of an integrity error in a global positioning system (GPS) signal transmitted from a transmitter in a global positioning system (GPS) satellite, the method comprising the steps of:
- detecting an error in the global positioning system (GPS) signal;
- quantifying an error amount for the error in the global positioning system (GPS) signal;
- setting an alert timing pattern for shifting the phase by a predetermined phase-shift amount in accordance with the quantified error amount;
- alerting the user of the error by shifting a phase of the global positioning system (GPS) signal from an initial value by the predetermined phase-shift amount in accordance with the alert timing pattern;
- correcting the error in the global positioning system (GPS) signal;
- confirming the correction to the user by shifting the phase of the global positioning system (GPS) signal by the predetermined phase-shift amount in accordance with a confirmation timing pattern;
- and
- returning the phase of the global positioning system (GPS) signal to the initial value.
A computing apparatus provided in a global positioning system (GPS) satellite for alerting a user of an integrity error in a global positioning system (GPS) signal transmitted from a transmitter in the global positioning system (GPS) satellite, the computing apparatus comprising:
- detecting means for detecting an error in the global positioning system (GPS) signal;
- alerting means for alerting the user of the error by shifting a phase of the global positioning system (GPS) signal from an initial value by a predetermined phase-shift amount;
- and
- returning means for returning, in the case that the detected error is corrected, the phase of the global positioning system (GPS) signal to the initial value.
Dependencies are inferred from the claim text.