Design and Test of Algorithms and Real-Time Receiver to use Universal Access Transceiver (UAT) for Alternative Positioning Navigation and Timing (APNT)

The FAA Alternative Positioning Navigation and Timing (APNT) effort is developing technologies to provide navigation service capable of sustaining operations in the event of the loss of Global Navigation Satellite Systems (GNSS). APNT will utilize existing ground infrastructure to support this capability. One effort is to examine the use of the Automatic Dependent Surveillance Broadcast (ADSB) ground infrastructure for ranging. This paper examines the use the one of transmitted ADS-B signals, Universal Access Transceiver (UAT). UAT signal is designed with passive range capability. This paper first discusses how to obtain the range from UAT. Then, a prototype UAT receiver is designed to implement the concepts. Finally, a ground test uses the transmitted, on-air signal to examine the ranging and positioning of the receiver. The field test results are presented demonstrating the ability of UAT to support APNT.