Patent ID: 11921223
Assignee: NOVATEL INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A computer implemented method to determine whether a spoofing attack is occurring, the computer implemented method comprising:
receiving signals at a first antenna and a second antenna; and
performing a channel distortion authentication procedure, wherein the channel distortion authentication procedure comprises:
measuring a first double difference of a first pseudorange measurement of the signals;
determining whether a first value corresponding to the first double difference of the first pseudorange measurement exceeds a predefined pseudorange threshold; and
determining that the first value corresponding to the first double difference of the first pseudorange measurement does not exceed the predefined pseudorange threshold;
initiating an observation window that lasts a predefined amount of time after determining that the first value of the first double difference does not exceed the predefined pseudorange threshold,
determining that the signals are the authentic navigation signals if any one of a plurality of different new values, corresponding to a plurality of new double difference values obtained during the observation window, exceeds the predefined pseudorange threshold, and
determining that the signals are spoofing signals if all of the plurality of different new values, corresponding to the plurality of new double difference values obtained during the observation window, do not exceed the predefined pseudorange threshold.