Joint OTHR multipath state estimation with unknown ionospheric heights

This paper first considers over-the horizon radar (OTHR) target tracking in the unknown ionospheric heights case, and a new scheme for joint multipath data association, ionospheric heights identification and state estimation (JMAHE) is developed based on distributed expectation conditional maximization (ECM) framework. The proposed JMAHE scheme casts the OTHR multipath tracking problem as sensor network collaborative tracking, and has a two-level processing structure. The local level performs the local measurement selection, state estimation and ionospheric heights identification jointly based on ECM algorithm. Then, the global level fuses these local estimates by using the consensus strategy.