Evaluation & comparison of ranging using Universal Access Transceiver (UAT) and 1090 MHz Mode S Extended Squitter (Mode S ES)

The FAA Alternative Position Navigation and Timing 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 (ADS-B) ground infrastructure for ranging. This paper examines the use the two transmitted ADS-B signals: 1) 1090 MHz Mode S Extended Squitter (Mode ES) and Universal Access Transceiver (UAT). It uses the transmitted, on-air signal to examine multipath, ranging and timing performance.