Forward-scatter Doppler-only commercial airliner tracking

Abstract

Appearance of tragedies like the lost flight MH370 should be eliminated or reduced and in this paper a technique based on the Doppler shift of radio sources of opportunity is suggested as an alternative technique of tracking aircraft. Such systems are based on simultaneous analysis of the Doppler shift caused by aircraft moving with respect to multiple radio signal sources and network of receivers. One of the aspects of the technique is extraction of Doppler signatures from within spectrogram, for which a robust technique was developed and tested with a variety of different weather and terrain conditions and antenna configurations. The system was able to trace 73% of observed Doppler signatures. Among testing sessions one particular situation in which aircraft is beyond the visible horizon or over-thehorizon (OTH) was analysed with respect to capability of aircraft tracking with the transmitting-receiving network. Such radar system is designed as combination of peer to peer and server side protocols for exchanging information on Doppler shift and aircraft location, respectively. The multistatic configuration of the radar system is built out of three receiving and three transmitting stations located in south east part of Finland and adjoined part of Russian Federation. The efficiency and precision of the tracking system was estimated to OTH visibility and equaled 420km and 1500m, respectively. The precision of the tracking system was verified with reference data based on Automatic dependent surveillance - broadcast (ADS-B) information.