Method of monitoring the integrity of radio-navigation stations in a satellite based augmentation system

A monitoring and processing centre for satellite based augmentation system SBAS comprising means, including a processor, for monitoring the integrity of stations for observing radio-navigation signals, said means being configured for defining at least one geographical zone comprising a plurality of observation stations,

• calculating, for each observation station of the said zone and for each line of sight between the said station and a satellite, the discrepancy between a theoretical pseudo-distance D and a measured pseudo-distance D′,
• calculating the average m of the said discrepancies D−D′ over the said zone for at least one satellite in visibility of the said zone,
• validating the integrity of at least one observation station of the said zone if the discrepancy between the theoretical pseudo-distance D and the measured pseudo-distance D′, for the said station and for at least one line of sight between the said station and a satellite, is less than or equal to the said average that is multiplied by a predetermined exclusion threshold, and excluding this observation station in the converse case.