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Radio Frequency Interference Suppression for High-Frequency Ocean Remote Sensing Radar with Inter-Pulse Phase Agility
Heng Zhou1, Xiongbin Wu1, Liang Yu1
1School of Earth and Space Science and Technology, Wuhan University, Wuhan 430072, China.
Sensors (Basel, Switzerland)
|May 4, 2026
Summary
This study introduces a new method to reduce radio frequency interference (RFI) in ocean remote sensing radar. The technique preserves the sea echo Doppler spectrum, improving wind and wave parameter accuracy.
Area of Science:
- Ocean Remote Sensing
- Signal Processing
- Electromagnetics
Background:
- Accurate inversion of wind and wave parameters using high-frequency radar depends on the sea echo Doppler power spectrum.
- Radio frequency interference (RFI) distorts this spectrum, compromising inversion accuracy.
- Existing RFI suppression methods often neglect spectral power fluctuations caused by the suppression process.
Purpose of the Study:
- To develop a novel narrowband RFI suppression scheme for high-frequency ocean remote sensing radar.
- To mitigate RFI while minimizing distortion of the sea echo Doppler power spectrum.
- To improve the accuracy of wind and wave parameter inversion.
Main Methods:
- A combined approach using inter-pulse phase agility (IPA) and orthogonal projection (OP).
- Modulation of inter-pulse phases with an optimized aperiodic sequence to uniformly disperse sea echo power.
- Spatial OP to suppress RFI stripes in the range-Doppler spectrum, followed by phase compensation.
Main Results:
- Effective suppression of narrowband RFI.
- Significant alleviation of spectral distortion in the sea echo Doppler spectrum.
- Preservation of sea echo coherence and uniform dispersion of residual RFI power.
Conclusions:
- The proposed IPA and OP scheme offers a robust solution for RFI suppression in ocean remote sensing.
- This method enhances the reliability of sea echo Doppler spectrum analysis.
- Improved accuracy in wind and wave parameter inversion is achievable with this technique.
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