CPC G01S 19/015 (2013.01) [G01S 19/258 (2013.01); G08G 5/0013 (2013.01); H04W 72/23 (2023.01)] | 14 Claims |
1. A method of identifying and responding to a global positioning system (GPS) denial of service, said method comprising the steps of:
equipping an aircraft with a mode S airborne transponder;
configuring the aircraft's mode S transponder for transmitting a GPS-derived time-of-day as a message;
transmitting the aircraft's time-of-day message as a downlink format message using an available binary data storage (BDS) register;
configuring an aircraft surveillance system for receiving a GPS time-of-day message transmitted as a downlink format message;
receiving, by the aircraft surveillance system, the time-of-day message from the aircraft;
configuring the aircraft surveillance system for comparing the received time-of-day message from the aircraft to a comparison time of day;
validating reception of authentic GPS signals by the aircraft when the received time-of-day message is within a threshold amount of the comparison time of day;
indicating when the received time-of-day message is beyond the threshold amount of the comparison time of day; and
mitigating erroneous aircraft navigation when the received time-of-day message is beyond the threshold amount of the comparison time of day.
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