Propagation mode estimation: a prerequisite for OTH radar fusion

Over-the-horizon (OTH) radars operate in the high frequency (HF) band of the radar spectrum and utilize ionospheric reflections to detect and track targets in regions up to 2000 nautical miles from the radar site. OTH radars thus have the capability to serve as cost-effective sensors for detecting and tracking aircraft over large surveillance areas. In this paper we describe an algorithm for fusing data from multiple OTH radars. We show that estimation of the radar signal propagation mode is tightly coupled to the tracking and correlation functions in the fusion algorithm. Results using test data collected from two operational OTH radars show that fusion improves both track continuity and track accuracy