Hybrid AOA/DTOA Approach to 1090 MHz ADS-B Wide Area Multilateration

Abstract

This study develops a hybrid positioning scheme that combines both differential time of arrival (DTOA) and angle of arrival (AOA) observations of the 1090-MHz automatic dependent surveillance-broadcast (ADS-B) signal and implements it on a wide area multilateration (WAM) test bed. The major issue when combining DTOA and AOA observations is synchronization. A synchronization design for DTOA and AOA observations is thus evaluated. The positioning algorithm that combines AOA and DTOA observations is a filter-based approach. Based on the measurement errors from actual ADS-B signals received from real flights, simulation is used to evaluate the positioning performance of the proposed 1090-MHz ADS-B WAM with the integration of AOA/DTOA approach under two scenarios, namely DTOA alone and AOA combined with DTOA.