Improved detection and suppression of external interference in HF Surface Wave Radar

This paper presents a propagation-attenuation-model-based method to detect the ranges where ionospherically distorted signals in HF Surface Wave Radar (HFSWR) may become dominant. While the method can be used to detect the presence of both ionospheric clutter and skywave interference, this paper focuses on the detection of skywave interference only. The radar data in the detected ranges where skywave interference becomes dominant are then used in an External Interference Cancellation (EIC) algorithm to estimate the interference components in the radar channels. The results of the investigation show that, while the original EIC algorithm can cancel narrowband interference by up to 15 dB, the revised algorithm using the method presented by this paper can further improve the performance by up to 5 dB.