Simultaneous Tracking and Ionospheric Model Estimation for NG OTHR

Robust target tracking and accurate geo-location for over-the-horizon radar (OTHR) are currently limited by clutter-contamination of signal returns and uncertainty in the multi-mode mapping from radar to ground coordinates. In this proposal, we address both these challenges by developing methods which jointly estimate target ground positions and ionospheric model perturbations while optimally associating radar detections across multiple dwells. The proposed Simultaneous Target and Ionospheric Model Estimation (STIME) approach exploits non-maneuvering targets and/or known aircraft flight paths to both geo-locate targets and to track the variations in ionospheric parameters which frequently degrade the performance of current systems. Moreover, by incorporating estimates of ionospheric parameters into the target tracker, STIME greatly simplifies the subsequent association of multi-mode ground tracks. In principle, STIME is applicable to both current and next generation OTH radar. For NGOTHR, the proposed approach maximizes the utility of elevation angle measurements obtained using 2-D transmit and receive arrays by incorporating them early on in the tracking and data association process. BENEFIT: The proposed methods for improving multi-mode OTHR tracking and geo-location in the presence of ionospheric model uncertainty will benefit both current systems used for counter-drug enforcement as well as NGOTHR systems designed for wide-area surveillance of US coastlines in support of homeland defense.