The performance of low frequency Ultra-Wide-Band (UWB) Synthetic Aperture Radar (SAR) is seriously affected by narrow band Radio Frequency Interference (RFI) in the VHF/UHF band. RFI suppression, by placing notches over the energy spectra to remove the RFI spikes, results energy loss of the wide-band signals and raises the range direction side-lobes. This paper presents an approach to suppress the side-lobe in range direction caused by adaptive filtering. After clipping main energy of strong scatterers in range compression domain before RFI estimation, the interference signals are estimated using an Adaptive Line Enhancer (ALE) and subtracted from the radar echo. The clipping approach makes use of the different time-domain characteristics between wide-band signal and narrow band interference, and by using pulse compression technology the method can be processed efficiently. To investigate the performance of RFI suppression, clipping of strong scatterers is combined to the ALE based on Normalized Least Mean Square (NLMS) algorithm. Simulation results and experimental data test compared with the conventional algorithms suggest that side-lobes of the strong scatters can be reduced effectively in RFI suppression.
李悦丽. 基于强散射点剔除的自适应窄带RFI抑制滤波器[J]. 电子与信息学报, 2016, 38(7): 1758-1764.
LI Yueli. Narrow Band RFI Suppression via Adaptive Filtering with Clipping of Strong Scatterers. JEIT, 2016, 38(7): 1758-1764.
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