Patent ID: 7592952
Filing Date: 2009-09-22
Classification: G01S

Abstract:
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.