Spoofing detection based on ads-b positions from multi-mode s transponder intruders

A system comprising:

• an automatic dependent surveillance-broadcast (ADS-B) receiver;
• an active surveillance system;
• processing circuitry of a computing device, wherein the computing device is configured to be installed in an own-ship aircraft, the processing circuitry configured to:
• receive reports from a plurality of aircraft from the ADS-B receiver;
• receive TCAS transponder signals from the plurality of aircraft via the TCAS;
• calculate a pseudo-position based on a relative position of the own-ship aircraft to the plurality of aircraft based on received data comprising:
• a reported position of each aircraft of the plurality of aircraft based on decoding each received ADS-B report from each aircraft;
• and
• a calculated range and bearing to each aircraft of the plurality of aircraft based on the TCAS transponder signals;
• receive broadcast signals from one or more satellites of a global navigation satellite system (GNSS);
• calculate a GNSS position based on the received broadcast signals;
• determine whether the GNSS position is a spoofed GNSS position based on a comparison of the GNSS position to the pseudo-position;
• and
• in response to determining that the GNSS position is spoofed, use the pseudo-position for navigation of the own-ship aircraft.

A method comprising:

• receiving, by processing circuitry of a computing device automatic dependent surveillance-broadcast (ADS-B) reports from a plurality of aircraft, wherein the computing device is configured to be installed on an own-ship aircraft;
• receiving, by the processing circuitry, a traffic collision alert system (TCAS) transponder signal from the plurality of aircraft;
• calculating, by the processing circuitry, a pseudo-position based on a relative position of the own-ship aircraft to the plurality of aircraft based on received data comprising at least one of:
• a reported position of each aircraft of the plurality of aircraft based on decoding each received ADS-B report from each aircraft;
• and
• a calculated range and bearing to each aircraft of the plurality of aircraft based on the TCAS transponder signals;
• receiving broadcast signals from one or more satellites of a global navigation satellite system (GNSS);
• calculating a GNSS position based on the received broadcast signals;
• comparing, by the processing circuitry, the GNSS position to the pseudo-position;
• determining, by the processing circuitry, whether the GNSS position is a spoofed GNSS position based on the comparison;
• and
• in response to determining that the GNSS position is spoofed, using, by the processing circuitry, the pseudo-position for navigation of the own-ship aircraft.