Clutter Suppression Based on Spatial Polarimetric Spectral Characteristics of Airborne Animals for Weather Radar

Weather radar is an effective means for large-scale monitoring of airborne animals. However, both ground clutter and meteorological echoes can interfere with biological echoes, affecting the quality of monitoring data. Current frequency-domain filtering methods can only suppress ground clutter, and clutter suppression techniques based on spectral polarization can suppress both ground clutter and moving non-weather targets, but neither of these can meet the requirements for biological monitoring. To enhance the quality of biological data, this study proposes the clutter suppression method based on spatial polarimetric spectral characteristics of airborne animals for biological monitoring. For ground clutter, based on the value jumps of the spectral polarimetric observables, the clutter range in the Doppler spectrum is determined, and the clutter is suppressed. For meteorological echoes, based on the continuity differences in spectral polarimetric observables, weather suppression is achieved by using the statistical differences of the observables obtained by using a sliding window in the range-Doppler spectrogram. The results indicate that the quality of biological data has been improved after applying the proposed method to radar data collected by operational S-band weather radar. Compared to other methods, the proposed method demonstrates the best performance in suppressing non-biological clutter while preserving airborne animals.