Computer implemented method for detecting global navigation satellite system signal spoofing, a data processing apparatus, a computer program product, and a computer-readable storage medium

A computer-implemented method for detecting Global Navigation Satellite System, signal spoofing, the method comprising:

• a) digitizing, acquiring and tracking, at a receiver, a GNSS signal from at least one GNSS satellite, the GNSS signal comprising a predictable part and an unpredictable part, wherein the predictable part comprises predictable bits and the unpredictable part comprises unpredictable bits;
• b) storing, by the receiver, a sample sequence ypred*(n) of the predictable part and a sample sequence yunpred*(n) of the unpredictable part of the GNSS signal;
• c) verifying, by the receiver, a value of the unpredictable bits from which the unpredictable sample sequences are extracted;
• d) computing, by the receiver, a first partial correlation B′unpred between the unpredictable sample sequences and a locally stored GNSS signal replica x and a second partial correlation B′pred(k) between the predictable sample sequences and the locally stored GNSS signal replica x(n) by:
• B′unpred(k)=Σn=1samplesyunpred*(n)*x(n);
• and
• B′pred=Σn=1samplesypred*(n)*x(n),
• and removing a sign of the first partial correlation and the second partial correlation by Bunpred,pred(k)=b(k)B′unpred,pred(k) where b(k) is the value of the bit;
• e) calculating, by the receiver, a predefined metric R from the first and the second partial correlation, the predefined metric R being:
• R3=|1/NbΣk=1Nb(Bunpred(k)−Bpred(k));
• and
• f) comparing the predefined metric with a predefined threshold value to detect GNSS signal spoofing.