METHODS AND SYSTEMS TO INCREASE ACCURACY IN THE NAVIGATION OF SINGLE FREQUENCY RECEIVERS
First Claim
1. A method of mitigating errors in satellite navigation measurements, the method comprising:
- at a satellite navigation receiver;
receiving respective single-frequency signals from respective satellites in a plurality of satellites in a satellite navigation system;
in the absence of differential corrections, calculating pseudorange and carrier-phase measurements corresponding to respective ones of the received single-frequency signals, including filtering the pseudorange and carrier-phase measurements in a Kalman filter having a state vector comprising a plurality of states, the plurality of states including a position state, a receiver clock state, and a plurality of bias states, each bias state corresponding to a respective satellite in the plurality of satellites, the filtering including updating the state vector; and
updating an estimated position of the satellite navigation receiver in accordance with an update to the state vector;
wherein a respective bias state in the plurality of bias states accounts for ambiguity, residual satellite clock bias, satellite orbital error, and ionospheric delay associated with a respective satellite in the plurality of satellites.
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Accused Products
Abstract
In a method of mitigating errors in satellite navigation measurements at a satellite navigation receiver, respective single-frequency signals are received from respective satellites in a plurality of satellites in a satellite navigation system. Pseudorange and carrier-phase measurements corresponding to respective received single-frequency signals are calculated. These calculations include filtering the pseudorange and carrier-phase measurements in a Kalman filter having a state vector comprising a plurality of states, including a position state, a receiver clock state, and a plurality of bias states. Each bias state corresponds to a respective satellite in the plurality of satellites. The filtering includes updating the state vector. An estimated position of the satellite navigation receiver is updated in accordance with an update to the state vector.
38 Citations
24 Claims
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1. A method of mitigating errors in satellite navigation measurements, the method comprising:
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at a satellite navigation receiver; receiving respective single-frequency signals from respective satellites in a plurality of satellites in a satellite navigation system; in the absence of differential corrections, calculating pseudorange and carrier-phase measurements corresponding to respective ones of the received single-frequency signals, including filtering the pseudorange and carrier-phase measurements in a Kalman filter having a state vector comprising a plurality of states, the plurality of states including a position state, a receiver clock state, and a plurality of bias states, each bias state corresponding to a respective satellite in the plurality of satellites, the filtering including updating the state vector; and updating an estimated position of the satellite navigation receiver in accordance with an update to the state vector; wherein a respective bias state in the plurality of bias states accounts for ambiguity, residual satellite clock bias, satellite orbital error, and ionospheric delay associated with a respective satellite in the plurality of satellites. - View Dependent Claims (2, 3, 4, 5, 7, 8, 15, 17, 18, 19, 20, 21, 22)
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23. A satellite navigation receiver, comprising:
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an antenna to receive respective single-frequency signals from respective satellites in a plurality of satellites in a satellite navigation system; memory; one or more processors; and one or more programs stored in the memory and configured for execution by the one or more processors, the one or more programs including; instructions to calculate, in the absence of differential corrections, pseudorange and carrier-phase measurements corresponding to respective ones of the received single-frequency signals, including instructions to filter the pseudorange and carrier- phase measurements in a Kalman filter having a state vector comprising a plurality of states, the plurality of states including a position state, a receiver clock state, and a plurality of bias states, each bias state corresponding to a respective satellite in the plurality of satellites, the instructions to filter including instructions to update the state vector; and instructions to update an estimated position of the satellite navigation receiver in accordance with an update to the state vector; wherein a respective bias state in the plurality of bias states accounts for ambiguity, residual satellite clock bias, satellite orbital error, and ionospheric delay associated with a respective satellite in the plurality of satellites.
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24. A computer readable storage medium storing one or more programs for use in a satellite navigation receiver that receives respective single-frequency signals from respective satellites in a plurality of satellites in a satellite navigation system, the one or more programs configured to be executed by one or more processors in the satellite navigation receiver and comprising:
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instructions to calculate, in the absence of differential corrections, pseudorange and carrier-phase measurements corresponding to respective ones of the received single-frequency signals, including instructions to filter the pseudorange and carrier-phase measurements in a Kalman filter having a state vector comprising a plurality of states, the plurality of states including a position state, a receiver clock state, and a plurality of bias states, each bias state corresponding to a respective satellite in the plurality of satellites, the instructions to filter including instructions to update the state vector; and instructions to update an estimated position of the satellite navigation receiver in accordance with an update to the state vector; wherein a respective bias state in the plurality of bias states accounts for ambiguity, residual satellite clock bias, satellite orbital error, and ionospheric delay associated with a respective satellite in the plurality of satellites.
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Specification