Multipath track fusion for over-the-horizon radar

Over-the-horizon skywave radar exploits ionospheric propagation of HF signals to detect targets beyond the line-of-sight horizon. Multiple propagation paths between the radar sites and the target are often encountered, giving multiple resolved detections for a single target. An algorithm for the fusion of multipath tracks is outlined here which accounts for uncertainty in the coordinate registration transformation to ground coordinates. A multihypothesis track association procedure is described which may be appended to existing radar coordinate tracking filters. The probability for each feasible track association hypothesis is computed, and fused estimates for target states in ground coordinates are evaluated for each hypothesis.