| 摘要 |
589702 Disclosed is a method for protecting a radionavigation receiver from aberrant pseudo-range measurements. The method calculates an integrity indicator by calculating residuals of measurements of pseudo-ranges. The residuals of pseudo-range measurements are obtained from geographical position and clock shift data provided by a primary radionavigation receiver (1). The primary navigation receiver (1) obtains the data from measurements, for example from satellite transmissions. The residuals are denoted Yi, where i is the index of a satellite. The method includes the steps of: a) forming subsets of residuals of cardinal h=N-1 and/or N-2, wherein N is the number of residuals, b) calculating the standard deviation of each subset and determining hmin, Ymin and mmin wherein ?min is the smallest standard deviation, hmin is the value of cardinal for which ?min has been obtained, Ymin is the vector of corresponding cardinal hmin, and mmin is the mean of Ymin; c) calculating a first vector of residuals defined by: d) sorting the vectors rvec,1 in ascending order to obtain: e) calculating the factor f defined by: where (?2)-1(.,1) is the inverse of the ?2 statistical distribution with one degree of freedom; f) weighting ?min in the following manner: g) calculating a new vector of residuals: h) defining a threshold T such that: where P is a probability whose optimal value must be determined by probabilistic simulation; and i) comparing each element of rvec,2 with T and if rvec,2(i) > T a fault is declared to have been detected and satellite i is excluded.
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