| 摘要 |
The present invention provides methods and system for enabling a standalone navigation receiver capable of generating receiver specific predicted satellite orbits based on historical navigation data collected by and stored in the receiver. Thus, the navigation receiver is able to use the predicted satellite orbits to obtain better Time-To-First-Fix (TTFF) and position accuracy without the need of connecting to a remote server and the associated communications system. In an embodiment, a standalone navigation receiver having sufficient memory collects navigation data from navigation satellites and generates predicted satellite orbits using the collected navigation data. Under weak signal conditions when decoding of the navigation data is not possible, the receiver uses the predicted satellite orbits to predict the accurate satellite positions or the set of ephemeris and the associated pseudoranges. The predicted orbits may be accurate for several days without the reception of broadcast ephemeris.
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