Coordinate Registration Method based on Sea/Land Transitions Identification for Over-the-Horizon Sky-Wave Radar: Numerical Model and Basic Performance Requirements

We propose an approach to the problem of range coordinate registration (CR) for HF band over-the-horizon sky-wave radar (OTHR-SW) signals on a single pulse basis. The approach is based on the a priori knowledge of the displacement of the sea/land transitions within the area illuminated by the radar antenna beam. It takes advantage of the geomorphological structure of the surveillance area, which is exploited to build a surface correlation mask that is in turn used as a geographic reference for the received radar echo. The method is based on the maximization of the cross-correlation between the received radar echo and the surface mask signatures. We describe first an extended numerical model of the whole HF OTHR-SW scenario for simulating the received signal, then we show the results of the application of the method under simplifying operative hypotheses that allow to point out the minimum requirements in terms of received signal-to-noise ratio (SNR) and differential sea/land backscattering coefficient for achieving given accuracies in the range estimates.