Radio frequency interference suppression in small-aperture high-frequency radars

High-frequency (HF) radars have gained much attention in recent years due to their remarkable capabilities in remote sensing of sea surface states. Radio frequency interference (RFI) should be suppressed before extraction of useful information from the radar echoes. Element instead of array-based interference suppression method is preferred for a small-aperture radar, and it is still more difficult to deal with the nonstationary interference. In this letter, a short-time range domain cancellation method for RFI suppression is proposed, whose advantage over the global one is twofolded: better suppression performance and lower computation cost. Processing results of real data collected by OSMAR-S, a portable HF radar, show the validness of the short-time method for nonstationary RFI suppression. The method can greatly improve the anti-interference capability and detection performance of the HF radar.