The universal access transceiver (UAT) is interesting as an alternative pseudolite because pseudoranging is available using ground segment messages. However, there is a limitation that accurate ranging is not supported when the user altitude is low, because of geometrical and multipath effects. In this study, we investigated the application of the airborne relay-based positioning system (ARPS) to UAT, because the ARPS has the advantages of a ground-based and an airborne-based system and is well suited to the UAT frame. In a UAT-embedded ARPS, the reference stations transmit navigation signals in the ground segment and airborne relays transfer measured information in the automatic dependent surveillance broadcast (ADS-B) segment. To verify the feasibility of ARPS in UAT, we performed various simulations. The simulation results show that the ARPS can be operated in UAT to provide accurate positioning, although the mobility of airborne relays affects the accuracy of system.
['Kyuman Lee', 'Jaesung Lim', 'Sunju Choi']
A feasibility study of ARPS in UAT for positioning