| US 7,592,952 B2 | ||
| Method of locating a vehicle from satellite data | ||
| Charlie Vacher, Paris (France) | ||
| Assigned to Sagem Defense Securite, Paris (France) | ||
| Filed on Oct. 05, 2007, as Appl. No. 11/905,944. | ||
| Claims priority of application No. 06 08828 (FR), filed on Oct. 09, 2006. | ||
| Prior Publication US 2008/0084348 A1, Apr. 10, 2008 | ||
| Int. Cl. G01S 1/00 (2006.01); G01S 5/14 (2006.01) | ||
| U.S. Cl. 342—357.06 [342/357.02; 342/357.03] | 4 Claims |
| 1. A method of locating a moving element by determining a reference position and at least one overall protection limit from
data from a group of satellites in a constellation of satellites, the overall protection limit calculation comprising the
step of calculating protection limits as a function of probabilities for the absence of failure in the constellation of satellites,
and of failure in the constellation of satellites, the method comprising the steps of:
from the group of satellites, selecting a subgroup comprising at least five satellites;
calculating a main position from the data from a group of satellites;
calculating secondary positions from the data from a subgroup of satellites by excluding date from one of the satellites when
calculating each secondary position;
calculating protection limits corresponding to the main and secondary positions while distinguishing whether the failure in
the constellation does or does not affect the satellites taken into consideration; and
calculating the overall protection limit from the reference position, the main position, the secondary positions, and the
protection limits corresponding to the main and secondary positions.
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