| US 7,564,406 B2 | ||
| Method and apparatus in standalone positioning without broadcast ephemeris | ||
| Shaowei Han, Palo Alto, Calif. (US) | ||
| Assigned to SiRF Technology, Inc., San Jose, Calif. (US) | ||
| Filed on Nov. 10, 2006, as Appl. No. 11/558,614. | ||
| Prior Publication US 2008/0111738 A1, May 15, 2008 | ||
| Int. Cl. G01S 1/00 (2006.01) | ||
| U.S. Cl. 342—357.12 | 22 Claims |
| 1. A method for a satellite navigation receiver, comprising:
storing current and historical broadcast ephemeris received from a satellite in a local navigation database on the receiver;
estimating perturbation forces for the satellite from the stored current and historical broadcast ephemeris;
estimating an initial satellite position for the satellite from the stored current and historical broadcast ephemeris and
the estimated perturbation forces;
computing predicted ephemeris for the satellite using the estimated perturbation forces and the estimated initial satellite
position; and
determining a position for the satellite navigation receiver using the predicted ephemeris.
|