Ephemeris extension method for GNSS applications
AssigneeNemerix SA
InventorLionel Garin
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Abstract
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.
Claims19
A method for improving the accuracy of a receiver position, comprising:
- receiving a prediction file comprising almanac correction data and fewer than 60480 bytes;
- using the almanac correction data with almanac data to produce a corrected satellite location;
- and
- using the corrected satellite location to calculate a receiver position;
- wherein the almanac correction data is usable for seven days to generate corrected satellite locations accurate to within thirty meters.
A method for generating an extended ephemeris prediction file, comprising:
- obtaining data comprising a prediction of a satellite orbit;
- computing correction terms related to a difference between the prediction of a satellite orbit and a second prediction resulting from almanac data;
- wherein the prediction file comprises less than 60480 Bytes and is usable for seven days to generate corrected satellite locations accurate to within thirty meters.
A computer readable medium having computer code embedded therein that, when executed, would carry out a method for generating an extended ephemeris prediction file, comprising:
- obtaining data comprising a prediction of a satellite orbit;
- computing correction terms related to a difference between the prediction of a satellite orbit and a second prediction resulting from almanac data;
- wherein the prediction file comprises less than 60480 Bytes and is usable for seven days to generate corrected satellite locations accurate to within thirty meters.
A GNSS receiver, comprising:
- a communications port for receiving an almanac correction model;
- a memory for storing almanac data;
- circuitry for receiving GNSS signals;
- and
- a processor for calculating the position of the receiver based on the received GNSS signals and the position of a GNSS transmitter as calculated from almanac data and the almanac correction model;
- wherein the processor is configured to use the almanac correction model to generate corrected satellite locations, wherein each such location generated during a seven-day period is accurate to within thirty meters.
Dependencies are inferred from the claim text.