Ephemeris extension method for GNSS applications

摘要

Systems, methods and devices for improving the performance of Global Navigation Satellite System (GNSS) receivers are disclosed. In particular, the improvement of the ability to calculate a satellite position or a receiver position where a receiver has degraded ability to receive broadcast ephemeris data directly from a GNSS satellite is disclosed. Correction terms can be applied to an approximate long-term satellite position model such as the broadcast almanac.

主权项

1. A method comprising:
storing in a memory of a receiver, a prediction file comprising satellite position prediction data associated with a plurality of satellites for defining predicted positions of each of the satellites, the satellite position prediction data comprising, for each respective satellite and a plurality of time intervals, a separate set of data corresponding to a predicted position of the respective satellite at each time interval; defining, by a processor, at least one separate correction value for each respective satellite, the at least one correction value being valid for use during at least one of the time intervals, the at least one separate correction value is weighted based, at least in part, on the time interval for which the at least one separate correction value is defined; storing in the prediction file, the at least one separate correction value for each respective satellite, in association with the separate set of data in the prediction file corresponding to the predicted position of the respective satellite; calculating, by the processor, at least one corrected satellite position of a respective one of the satellites at said at least one defined time interval by applying the correction value that is associated with the separate set of data corresponding to the predicted position for the respective one of the satellites; and estimating, by the processor, a position of the receiver based, at least in part on said at least one corrected satellite position.