The influence of ionospheric non-uniformity on the detection area of HF bistatic sky-wave radar

High-frequency bistatic/multistatic sky-wave radars have various advantages such as anti-stealth capability, concealment, and high precision. However, they are vulnerable to the influence of the ionospheric transmission channel. This paper conducts simulation and experimental studies on the impact of the ionospheric inhomogeneous characteristics on the radio wave propagation of high-frequency bistatic sky-wave radars. Firstly, the radio wave propagation mode of high-frequency bistatic sky-wave radars is analyzed. In response to the ionospheric inhomogeneous characteristics and their impact on the sky-wave propagation path, simulation studies are carried out using the International Reference Ionosphere (IRI) model and the ray tracing method. An experimental study on the influence of ionospheric inhomogeneity on clutter energy is conducted by using a high-frequency bistatic sky-wave radar experimental system constructed with shortwave transceiver equipment. The results show that the ionospheric inhomogeneous characteristics have a significant impact on the possibility of the sky-wave propagation path. In the application scenarios of high-frequency bistatic sky-wave radars, it will cause significant changes in the detectable area of the target with frequency and azimuth, thus affecting the detection performance of the radar system for the target. The research of this paper provides a theoretical and practical basis for the design and application of high-frequency bistatic sky-wave radars.