Method for checking the integrity of a satellite radionavigation signal

A method for checking an integrity of processing of a radionavigation signal emitted by a satellite (SATi) of a satellite positioning system, said radionavigation signal being received by a receiver comprising reception means and processing means, said processing means comprising a linear anti-interference filter, said integrity checking method comprises at least a first phase of detection of a risk of false lock-on comprising the following steps:

• receiving the radionavigation signal at the reception means, the radionavigation signal having a nominal theoretical self-correlation function (A0);
• processing the radionavigation signal in an anti-interference processing module by the linear anti-interference filter implemented by the anti-interference processing module over a defined integration period (Tmean) to determine a mean impulse response;
• determining with a location determination module a mean theoretical self-correlation function (A) of said radionavigation signal received based on the mean impulse response and the nominal theoretical self-correlation function (A0);
• determining with the location determination module a number of local maxima of the mean theoretical self-correlation function (A) that comprises a modulus of the mean theoretical self-correlation function (A) or a modulus squared of the mean theoretical self-correlation function (A);
• and
• determining with the location determination module a risk of false lock-on when said number of local maxima is greater than or equal to two and triggering an alarm.