Satellite signal spoof detection using time-differenced carrier phase computed acceleration meeting integrity criteria

A system to detect spoofing or jamming of global navigation satellite system (GNSS) signals, the system comprising:

• a GNSS receiver onboard a vehicle;
• an inertial navigation system (INS) onboard the vehicle;
• an inertial measurement unit (IMU) operatively coupled to the INS, the IMU operative to produce inertial measurements that are sent to the INS;
• at least one processor onboard the vehicle, the at least one processor operative to receive data outputs from the GNSS receiver and the INS, the at least one processor operative to execute processor readable instructions to perform a spoofing or jamming test comprising:
• providing multiple derived acceleration test methods comprising:
• a first test method that uses GNSS-derived acceleration estimates and INS-derived acceleration estimates that are computed at a single time epoch;
• a second test method that uses GNSS-derived acceleration estimates and INS-derived acceleration estimates that are computed at two time epochs;
• and
• a third test method that uses GNSS-derived accelerations and INS-derived accelerations that are computed at multiple time epochs, using exponentially averaged accelerations;
• producing a time-varying threshold signal, indicative of a spoofing or jamming event, based on a user-specified probability of false alarm or probability of missed detection, for each of the derived acceleration test methods;
• obtaining a difference signal between the time-averaged GNSS-derived acceleration estimates and the time-averaged INS-derived acceleration estimates in each of the derived acceleration test methods;
• determining whether a magnitude of the difference signal is greater than the time-varying threshold signal in any of the derived acceleration test methods;
• and
• generating a spoofing or jamming alert when the magnitude of the difference signal is greater than the time-varying threshold signal in one or more of derived acceleration test methods.