US 11,841,444 B2
Resilient ephemeris decoding of GNSS satellite information
Jignesh Doshi, San Diego, CA (US); Tomohisa Takaoka, Tokyo (JP); and Yohei Kajikawa, Tokyo (JP)
Assigned to SONY GROUP CORPORATION, Tokyo (JP)
Filed by SONY CORPORATION, Tokyo (JP)
Filed on Jan. 11, 2021, as Appl. No. 17/145,783.
Claims priority of provisional application 63/071,247, filed on Aug. 27, 2020.
Prior Publication US 2022/0066050 A1, Mar. 3, 2022
Int. Cl. G01S 19/27 (2010.01); G01S 19/39 (2010.01); G01S 19/20 (2010.01)
CPC G01S 19/27 (2013.01) [G01S 19/20 (2013.01); G01S 19/39 (2013.01)] 15 Claims
OG exemplary drawing
 
8. A method, comprising:
in a positioning system:
decoding first ephemeris data of a satellite in a Global Navigation Satellite System (GNSS) satellite constellation;
estimating a first position of the satellite based on the decoded first ephemeris data, wherein
the satellite is estimated to be at the first position at a first time-instant;
estimating a deviation between the estimated first position of the satellite and a position where the satellite is expected to be at the first time-instant;
determining the estimated deviation to be above a threshold;
obtaining a previous ephemeris status of previous ephemeris data of the satellite, wherein
the previous ephemeris data precedes the first ephemeris data in time, and
the previous ephemeris status is one of a predicted ephemeris, an extended ephemeris, or a status which indicates that a previous position of the satellite is accurate for a position fixing operation;
excluding use of the estimated first position of the satellite in the position fixing operation of the positioning system, wherein the use of the estimated first position is excluded based on:
the determination that the estimated deviation is above the threshold, and
the obtained previous ephemeris status of the previous ephemeris data;
decoding second ephemeris data of the satellite subsequent to the exclusion of the use of the estimated first position;
estimating a second position of the satellite based on the decoded second ephemeris data, wherein
the satellite is estimated to be at the second position at a second time-instant;
determining one of agreement or disagreement of the estimated second position of the satellite with the first position of the satellite; and
controlling, based on the one of determined agreement or disagreement, a position filter of the positioning system to use the estimated second position of the satellite in the position fixing operation.