Mitigation of Radio Frequency Pulse Interference on Dual-Pol Weather Radar

Radio frequency interference (RFI) has gotten growing attention by weather radar community for the last decade. RFI could come from various radio devices (e.g., radars, wireless internet devices, etc.) and show different interference characteristics on weather radar data. Therefore, there have not been well established methods that could effectively mitigate all kinds of RFI signals.

In terms of waveform type of interference source, the RFI can be recognized as continuous interference and pulse interference. The continuous interference generally causes strong contamination in the whole radial path, where the interference source is located. The weaker contamination might appear in the adjacent directions, depending on the radar antenna sidelobe pattern. Normally, if the location of RFI source is known, the radials of contamination can be easily identified. The pulse interference, however, is more complicated. RFI may appear in all the directions and contaminate the variable range gates (i.e., number and bins) in every radar scan. The contamination is dynamic sweep by sweep and related to the pulse repetition frequency (PRF) of both weather radar and interference source.

The current study investigates the characteristics of pulse interference in dual-pol weather radar data, not only the interference pattern that is related to PRF, but also the dual-pol characteristics of interference signals. Based on the analysis results, a signal processing method is proposed for identifying and mitigating the pulse interference contamination in a dual-pol weather radar. The inhouse C-band radar of Enterprise Electronics Corporation (EEC), deployed in Enterprise, Alabama, is used for the experiments. The results well demonstrate the potential of proposed method for the RFI mitigation.