Resilient Multi-static Forward-scatter Network For Wide Area Air Traffic Monitoring

Use of illuminators of opportunity has made passive air traffic monitoring possible. In this paper the concept of a forward-scatter network for air traffic monitoring is introduced. Doppler-only from VHF multi-static radar is used to track aircraft, which as a configuration is a challenging way of tracking aircraft. Doppler shift can be easily determined from aircraft's location, but determining its location from the Doppler shift is not directly possible. An inverse approach with the Extended Kalman filter is used to track aircraft position instead. The tracker is initialized with real flight data, but updates on location are done with Doppler-only measurements. The validity of the tracking system is verified with reference data based on Automatic dependent surveillance - broadcast (ADS-B) information.