Patent ID: 9291714
Filing Date: 2016-03-22
CPC Classification: G01S

Claim Text:
1. A method for checking the integrity of position information delivered by a satellite positioning device (GNSS) comprising a bank of Kalman filters each providing a navigation solution (dX 0 , dXi, dXn) from raw measurements of signals transmitted by satellites, characterized in that for each filter of the bank, it includes the steps of: determining for each satellite at least one likelihood ratio (lr, lr′) between an assumption of a failure of a predetermined type of the satellite and an assumption of absence of failure of the satellite; comparing the likelihood ratio (lr, lr′) associated with the failure of the predetermined type with a threshold value, and if required declaring the failure of the predetermined type; estimating an error induced by the declared failure on the navigation solution provided by the filter, (i) correcting the navigation solution provided by the filter according to said estimate of the error induced by said on the navigation solution; (ii) calculating a cross-innovation reflecting the deviation between an observation corresponding to a raw measurement from a satellite not used by the filter and an a posteriori estimate of said observation from the navigation solution provided by the filter and corrected according to step (i); (iii) conducting a statistical test of the cross-innovation in order to declare whether the satellite, for which the raw measurement is not used by the filter, is faulty or not.