A method for determining a wrong synchronization of a receiver with a satellite during an acquisition phase for acquiring a navigation signal coming from the satellite, the satellite belonging to a global navigation satellite system;
- the navigation signal comprising a data channel including an item of navigation information modulated by a data spreading code specific to the satellite and carried by a carrier wave, and a pilot channel including a pilot spreading code specific to the satellite and carried by a carrier wave;
- during the acquisition phase, the receiver being able to receive the navigation signal, called received signal transmitted by the satellite, to generate a local data signal including a local image of the data spreading code and a local image of the carrier wave, and to generate a local pilot signal including a local image of the pilot spreading code and the local image of the carrier wave;
- the method being implemented after the acquisition phase during a convergence phase and comprising at least one of the following steps:
- determining a plurality of periodic pilot channel correlations each corresponding to a periodic correlation on a reference interval of duration equal to a reference value between the received signal and the local pilot signal, and a plurality of periodic data channel correlations each corresponding to a periodic correlation on one of the reference intervals between the received signal and the local data signal, and determining a first value as a function of these periodic correlations;
- determining a plurality of pilot channel partial correlations each corresponding to a periodic correlation on an interval of duration equal to a fraction of the reference value between the received signal and the local pilot signal, and determining a second value as a function of these partial correlations;
- determining a plurality of shifted pilot channel correlations each corresponding to a shifted correlation on one of the reference intervals between the received signal and a shifted local signal corresponding to the local pilot signal in which the local image of the pilot spreading code is shifted by an integer number of reference units, and determining a third value as a function of these shifted pilot channel correlations;
- the convergence phase further comprising the following step:
- determining a wrong synchronization when at least one of the values among the first value, the second value and the third value, when such a value is determined, exceeds a predetermined threshold;
- wherein the first value is determined based on covariances between the periodic pilot channel correlations and the periodic data channel correlations.