Anti-spoofing system for gnss receivers

A method comprising:

• receiving wireless signals transmitted by a plurality of global navigation satellite system (GNSS) satellites having a plurality of signals types;
• for each particular signal type of the plurality of signal types:
• excluding the particular signal type;
• calculating a parameter of a GNSS receiver based on the wireless signals received from a subset of the plurality of GNSS satellites having a plurality of remaining signal types;
• and
• calculating a residual score based on a variability associated with calculating the parameter, the residual score being one of a plurality of residual scores;
• identifying an outlier of the plurality of residual scores;
• and
• identifying which of the plurality of signal types includes a spoofing signal based on the outlier.

A non-transitory computer-readable medium comprising instructions that, when executed by a processor, cause the processor to perform operations comprising:

• receiving wireless signals transmitted by a plurality of global navigation satellite system (GNSS) satellites having a plurality of signals types;
• for each particular signal type of the plurality of signal types:
• excluding the particular signal type;
• calculating a parameter of a GNSS receiver based on the wireless signals received from a subset of the plurality of GNSS satellites having a plurality of remaining signal types;
• and
• calculating a residual score based on a variability associated with calculating the parameter, the residual score being one of a plurality of residual scores;
• identifying an outlier of the plurality of residual scores;
• and
• identifying which of the plurality of signal types includes a spoofing signal based on the outlier.