METHOD FOR OPERATING A PLURALITY OF GNSS RECEIVERS FOR DETECTING SATELLITE SIGNAL DEFORMATION

摘要

A test metric for satellite sent GNSS code signals is proposed, wherein a signal sent by each satellite i is received at different GNSS receivers, and bias-removed, averaged over the receivers and normalized measurement values are derived out of autocorrelation function values. A correlation matrix R_i,n is built from a matrix X_i,n containing the measurement values in the form of measurement value vectors {right arrow over (X)}_i,k from the present time epoch t_n and from previous time epochs t_k with k=1, . . . , n−1, wherein a principal component analysis is done of matrix R_i,n, wherein a transformed vector {right arrow over (T)}_i,n=PC_i,n^T·{right arrow over (X)}_i,n^T is calculated, with PC_i,n containing at least two eigenvectors having the largest eigenvalues of all eigenpairs. A signal quality monitor test metric SQM_i,n is built from the square sum of the entries of transformed vector {right arrow over (T)}_i,n, and if SQM_i,n is larger than a threshold THR, the satellite signals are disallowed for position determination at all GNSS receivers.