Satellite navigation using long-term navigation information
First Claim
1. A method of providing satellite-based navigation at a navigation device, the method comprising:
- receiving long-term navigation information at the navigation device from a communication system, wherein the long-term navigation information is associated with a nominal orbital path of a navigation satellite for a time period longer than approximately 24 hours, wherein the navigation satellite has an actual orbital path that is repeatedly adjusted to substantially conform to the nominal orbital path;
estimating at the navigation device a position of the navigation satellite using the long-term navigation information;
repeating at the navigation device the receiving and the estimating operations for a plurality of additional navigation satellites using long-term navigation information associated with each of the additional navigation satellites;
determining at the navigation device a position of the navigation device based on the estimated positions of the navigation satellite and the additional navigation satellites; and
wherein the actual orbital path adjustment and the long-term navigation information permit the estimating, repeating, and determining to be performed during the time period without requiring updated navigation information.
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Abstract
An improved approach to satellite-based navigation (e.g., GPS) is provided. In one embodiment, a method includes receiving a first set of tracking information. A nominal orbital path for the navigation satellite is determined using the first set of tracking information. Ephemeris data corresponding to the nominal orbital path is computed and uploaded to the navigation satellite. Long-term navigation information corresponding to the nominal orbital path is transmitted to a communication system for broadcast to a plurality of navigation devices. A second set of tracking information is received, an orbital path of the navigation satellite using the second set of tracking information is predicted, and a difference between the predicted orbital path and the nominal orbital path is determined. Commands configured to instruct the navigation satellite to adjust an actual orbital path of the navigation satellite to substantially conform to the nominal orbital path are uploaded to the navigation satellite.
33 Citations
16 Claims
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1. A method of providing satellite-based navigation at a navigation device, the method comprising:
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receiving long-term navigation information at the navigation device from a communication system, wherein the long-term navigation information is associated with a nominal orbital path of a navigation satellite for a time period longer than approximately 24 hours, wherein the navigation satellite has an actual orbital path that is repeatedly adjusted to substantially conform to the nominal orbital path; estimating at the navigation device a position of the navigation satellite using the long-term navigation information; repeating at the navigation device the receiving and the estimating operations for a plurality of additional navigation satellites using long-term navigation information associated with each of the additional navigation satellites; determining at the navigation device a position of the navigation device based on the estimated positions of the navigation satellite and the additional navigation satellites; and wherein the actual orbital path adjustment and the long-term navigation information permit the estimating, repeating, and determining to be performed during the time period without requiring updated navigation information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 15)
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10. A navigation device comprising:
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means for receiving long-term navigation information from a communication system, wherein the long-term navigation information is associated with nominal orbital paths of a plurality of navigation satellites for a time period longer than approximately 24 hours, wherein the navigation satellites have actual orbital paths that are repeatedly adjusted to substantially conform to the nominal orbital paths; and a processor adapted to; estimate positions of the navigation satellites using the long-term navigation information, determine a position of the navigation device based on the estimated positions of the navigation satellites, and wherein the actual orbital path adjustments and the long-term navigation information permit the estimate and determine operations to be performed during the time period without requiring updated navigation information. - View Dependent Claims (11, 12, 13, 14, 16)
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Specification