Over-the-horizon radar target tracking using multi-quasi-parabolic ionospheric modelling

Abstract

As over-the-horizon radar (OTHR) uses ionosphere reflection to detect and track targets, they are faced with a possible appearance of multi-paths and difficulties in estimating the target's ground location. The multi-quasi-parabolic (MQP) model is a sophisticated ionosphere model from which the electromagnetic waves' propagation can be deduced, as long as the measurement of the elevation angle is known. As the French OTHR Nostradamus measures this angle, the use of this model is proposed to improve target-tracking. This model is directly taken into account in the tracking algorithm equations. Here, the target's ground location estimation is specifically tackled and a method is proposed to handle MQP parameters even if elevation angle measurement resolution is poor. The proposed algorithm, based on a particle filter, enables the estimated model parameters to be dealt with and is able, in some circumstances, to ameliorate their estimations. This approach, applied to OTHR Nostradamus, is compared to a geometric one with numerical simulations and a real data example.