Patent ID: 7924221

Claim:
A method for monitoring the integrity of satellite navigation signals, said method comprising: a first detection of integrity problems, in which the same entity of a navigation signal from a specific satellite is received at different sites, and evaluated to estimate both the error in the entity and the error introduced by the error estimation; a second detection of integrity problems, in which at least one measurement of one or more received navigation signals from a specific satellite is carried out, and the at least one measurement is evaluated to estimate both the error in the entity and the error introduced by the error estimation; subsequently, a third detection of integrity problems in which a plurality of navigation signals from different satellites are measured and jointly evaluated to estimate both the error in the entity and the error introduced by the error estimation; wherein integrity problems of the satellite navigation signals are detected using results of the first, second and third detections in combination; wherein the first and second detections detect different types of integrity problems and integrity problems which are detectable during the first and second detections are taken into account if they occur during the third detection and have not been discovered during the first and second detection.