Position Determination Using Local Time Difference
First Claim
1. A position determination system, the system comprising:
- a communication and timing module configured to;
receive a plurality of signals, the plurality of signals transmitted from one or more ground transmitters and each of the plurality of signals relayed via one or more relay devices, andassociate a local receipt time with each of the plurality of signals upon receipt of the signals;
a measured range difference module configured to;
determine measured time receipt differences from the associated local receipt times for each pair of the plurality of signals, anddetermine a range difference for each of the plurality of signals based on the measured time receipt differences for each of the pairs of the plurality of signals;
a predicted range difference module configured to;
determine a hypothesized user position, anddetermine hypothesized range differences based on the hypothesized user position;
an optimization module configured to;
determine an estimation difference for each of the plurality of signals based on the range difference and the hypothesized range difference for each of the plurality of signals based on a figure of merit, andminimize the figure of merit based on a plurality of hypothesized user positions and an optimization routine ; and
a user position module configured to output a user position based on the a hypothesized user position associated with the minimized figure of merit.
1 Assignment
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Accused Products
Abstract
Described are computer-based methods and apparatuses, including computer program products, for determining a position. In some examples, the method includes determining measured time receipt differences from associated local receipt times for each pair of plurality of signals; determining a range difference for each of the plurality of signals based on the measured time receipt differences for each of the pairs of the plurality of signals; determining hypothesized range differences based on a hypothesized user position; determining an estimation difference for each of the plurality of signals based on the range difference and the hypothesized range difference for each of the plurality of signals based on a figure of merit; minimizing the estimation difference for the figure of merit based on a plurality of hypothesized user positions and an optimization routine; and outputting a user position based on a hypothesized user position associated with the minimized figure of merit.
5 Citations
14 Claims
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1. A position determination system, the system comprising:
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a communication and timing module configured to; receive a plurality of signals, the plurality of signals transmitted from one or more ground transmitters and each of the plurality of signals relayed via one or more relay devices, and associate a local receipt time with each of the plurality of signals upon receipt of the signals; a measured range difference module configured to; determine measured time receipt differences from the associated local receipt times for each pair of the plurality of signals, and determine a range difference for each of the plurality of signals based on the measured time receipt differences for each of the pairs of the plurality of signals; a predicted range difference module configured to; determine a hypothesized user position, and determine hypothesized range differences based on the hypothesized user position; an optimization module configured to; determine an estimation difference for each of the plurality of signals based on the range difference and the hypothesized range difference for each of the plurality of signals based on a figure of merit, and minimize the figure of merit based on a plurality of hypothesized user positions and an optimization routine ; and a user position module configured to output a user position based on the a hypothesized user position associated with the minimized figure of merit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for position determination, the method comprising:
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receiving a plurality of signals, the plurality of signals transmitted from one or more ground transmitters and each of the plurality of signals relayed via one or more relay devices; associating a local receipt time with each of the plurality of signals upon receipt of the signals; determining measured time receipt differences from the associated local receipt times for each pair of the plurality of signals; determining a range difference for each of the plurality of signals based on the measured time receipt differences for each of the pairs of the plurality of signals; determining a hypothesized user position; determining hypothesized range differences based on the hypothesized user position; determining an estimation difference for each of the plurality of signals based on the range difference and the hypothesized range difference for each of the plurality of signals based on a figure of merit; minimizing the estimation difference for the figure of merit based on a plurality of hypothesized user positions and an optimization routine; and outputting a user position based on the hypothesized user position associated with the minimized figure of merit. - View Dependent Claims (10, 11, 12, 13)
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14. A computer program product, tangibly embodied in an information carrier, the computer program product including instructions being operable to cause an information processing apparatus to:
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receive a plurality of signals, the plurality of signals transmitted from one or more ground transmitters and each of the plurality of signals relayed via one or more relay devices; associate a local receipt time with each of the plurality of signals upon receipt of the signals; determine measured time receipt differences from the associated local receipt times for each pair of the plurality of signals; determine a range difference for each of the plurality of signals based on the measured time receipt differences for each of the pairs of the plurality of signals; determine a hypothesized user position; determine hypothesized range differences based on the hypothesized user position; determine an estimation difference for each of the plurality of signals based on the range difference and the hypothesized range difference for each of the plurality of signals based on a figure of merit; minimize the estimation difference for the figure of merit based on a plurality of hypothesized user positions and an optimization routine; and output a user position based on a hypothesized user position associated with the minimized figure of merit.
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Specification