Navigation signal receiver trajectory determination
First Claim
1. A method of obtaining an accurate navigation receiver trajectory at a receiver, comprising:
- computing a receiver trajectory based on non-current ephemeris or a predicted satellite orbit, wherein the predicted satellite orbit is generated at the receiver based on prior satellite navigation messages received by the receiver; and
correcting the computed receiver trajectory to obtain a corrected receiver trajectory, wherein the corrected trajectory is a function of an approximate initial position and the computed receiver trajectory obtained using the non-current ephemeris or the predicted satellite orbit and, wherein correcting the computed trajectory comprises;
computing a computed initial position of the receiver using the non-current ephemeris;
computing a difference in position between the computed initial position and the approximate initial position; and
shifting the computed receiver trajectory by the difference.
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Accused Products
Abstract
The present invention provides methods and systems that enable a mobile navigation receiver to accurately determine its trajectory with non-current ephemeris in stand-alone mode. In an embodiment, the receiver computes the position for the same location using non-current ephemeris and current ephemeris at different time instances. The receiver then determines a position correction by finding the difference between these two computed positions, and applies this correction to the trajectory generated with non-current ephemeris to obtain a more accurate trajectory. In another embodiment, the receiver computes an initial position of the receiver using non-current ephemeris and finds the difference between the computed initial position and an accurate approximation of the initial position. The receiver then shifts the subsequent receiver trajectory computed using non-current ephemeris by the difference to obtain a more accurate trajectory.
24 Citations
18 Claims
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1. A method of obtaining an accurate navigation receiver trajectory at a receiver, comprising:
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computing a receiver trajectory based on non-current ephemeris or a predicted satellite orbit, wherein the predicted satellite orbit is generated at the receiver based on prior satellite navigation messages received by the receiver; and correcting the computed receiver trajectory to obtain a corrected receiver trajectory, wherein the corrected trajectory is a function of an approximate initial position and the computed receiver trajectory obtained using the non-current ephemeris or the predicted satellite orbit and, wherein correcting the computed trajectory comprises; computing a computed initial position of the receiver using the non-current ephemeris; computing a difference in position between the computed initial position and the approximate initial position; and shifting the computed receiver trajectory by the difference. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of obtaining an accurate navigation receiver trajectory at a receiver, comprising:
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computing a receiver trajectory based on non-current ephemeris or a predicted satellite orbit, wherein the predicted satellite orbit is generated at the receiver based on prior satellite navigation messages received by the receiver; and correcting the computed receiver trajectory to obtain a corrected receiver trajectory, wherein pseudoranges and clock error of new satellites entering the constellation are corrected. - View Dependent Claims (9)
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10. A navigation signal receiver, comprising:
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a radio frequency (RE) front-end for receiving satellite signals; a baseband section for processing received signals into correlation values; a processor coupled to the baseband section; and a computational module coupled to the processor, wherein the computational module computes a receiver trajectory using non-current ephemeris, and corrects the computed receiver trajectory to generate an accurate receiver trajectory, wherein the computational module corrects the computed trajectory by; computing a computed initial position of the receiver using the non-current ephemeris; computing a difference in position between the computed initial position and an approximate initial position; and shifting the computed receiver trajectory by the difference. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A navigation signal receiver, comprising:
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a radio frequency (RF) front-end for receiving satellite signals; a baseband section for processing received signals into correlation values; a processor coupled to the baseband section; and a computational module coupled to the processor, wherein the computational module computes a receiver trajectory using non-current ephemeris, and corrects the computed receiver trajectory to generate an accurate receiver trajectory, wherein pseudoranges and clock error of new satellites entering the constellation are corrected. - View Dependent Claims (18)
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Specification