Comparisons of Doppler Spectral Density Data by Different Bands Pointing Vertically Radars

The attenuation of the radar echo has always been a difficult problem in radar detections. Results corrected by the common methods have some differences with the real detecting value. Due to the richness of the micro physical and dynamic information by the power spectrum data of vertical detecting radars, the mechanism of attenuation could be investigated in the power spectrum layer. And then, a direction of the improvement of attenuation correction could be found by power spectrum data.Comparative research is carried out using the power spectrum data by Ka-band millimeter-wave radar, C-band frequency-modulated continuous-wave radar and Ku-band micro rain radar at Yangjiang of Guangdong during May-June in 2014 and Longmen of Guangdong during April-May in 2016. The power spectrum shapes by three radars are almost consistent, especially for the peak velocity and the first atmospheric signal, indicating data of three radars are reliable. In the detection of big particle size precipitation, the radar echo is affected by Mie scattering effects, especially shorter wavelength echoes. The reflect of Mie scattering effects on the power spectrum is a rapid decline of echo intensity during a speed point, which shrink the tail end of the spectrum, reduce signal spectrum width and affect the intensity value. The performance of power spectrum is the overall down of spectrum, and it leads to underestimation. In convective cloud precipitation detections, results calculated by the normal empirical formula may have difference with real value. Spectrum distribution could be taken into account in such condition, and the correction methods should be improved by the power spectrum density layer.Finally, the study of the attenuation correction, especially the study in the strong precipitation process, the power spectrum data could be used. But the question how the attenuation effect the power spectrum, the study just offers a direction. It still needs to explore in the quantitative research.