IJCAS

The surveillance sensor that has been mainly used for target tracking in air traffic control (ATC) environment is radar. The automatic dependent surveillance – broadcasting (ADS-B), which is based on the technologies of global navigation satellite systems, is recently participating in ATC systems. Although ADS-B provides more accurate measurements than does radar, it needs careful considerations for the application of the ATC systems. This is due to the fact that the reliability of ADS-B measurements is dependent upon each aircraft whereas that of radar is not. This study proposes a system for the estimation fusion of multiple heterogeneous sensors, which includes radar and ADS-B, whose measurements and sensor characteristics are different from one another. A centralized fusion architecture based on three-dimensional earth-centered earth-fixed (ECEF) common coordinate system is adopted to process the data received asynchronously from multiple heterogeneous sensors. In case of the ADS-B, the validity of the sensor data for each aircraft is checked using not only the accuracy and integrity information of the aircraft, but also a comparison of the ADS-B data with the radar data. This study also proposes variable-sized measurement vectors and matrices for the tracking filter in order to dynamically reflect the availability of the additional measurements from the downlinked aircraft parameters (DAP) which can be obtained from mode-S radar and ADS-B. The simulation results indicate that the proposed fusion system can improve the tracking performance with the advantages of different types of surveillance sensors.

Keywords: ADS-B, estimation, fusion, radar, surveillance.