The factors such as the turbulence and the sensitivity of radar detection affect, the Doppler spectral and, introduce error of the air vertical motion velocity and Rain Drop Size Distributions (DSD) retrievals with single wavelength cloud radar.However, the dual-wavelength cloud radar, which uses the differences of reflectivity spectra density for two wavelengths due to Mie scattering, not only improves the detection accuracy of the air vertical motion velocity and DSD, but also reduces the errors of the attenuation correction.A Ka/Ku dual-wavelength cloud radar in Chinese Academy of Meteorological Sciences was used to observe clouds and precipitations in Longmen, Guangdong Province.In this paper, under the assumption of the Gamma’s DSD, the effects of temperature and turbulence on the ratio of Ka-band and Ku-band reflectivity density spectra and their relationships with DSD parameters were analyzed, the effects of the sensitivity of the cloud radar on retrieved air vertical velocity, DSD and attenuation correction were simulated, The advantages of the Ka/Ku dual-wavelength radar on detecting micro-precipitation dynamics and microphysical parameters were discussed.The results show that, the variations of temperature affect the value of maximum ratio of the power spectrum for the two bands, but don’t affects the peak position.The effects of turbulence on the peak position are less than 0.5 m·s-1.Secondly, the effects of turbulence, and reflectivity sensitivity on air vertical velocities retrieved by single-band cloud radar are far greater than that by dual-wavelength cloud radar.Turbulence underestimated the air vertical velocity and the low, radar sensitivity overestimated it.Thirdly, for single wavelength cloud radar, turbulence expanded the DSD, underestimated the number contend for small drops, liquid water content (LWC) and attenuation coefficient.Low radar sensitivity narrowed the DSD, overestimated the number contend for small drops, LWC and attenuation coefficient.Finally, the precipitation cases during April 15 and 16, 2019 were chosen to examine the retrieval of air vertical motion and compared with the simulation result.The work provides base for retrieval of the microphysical and dynamic parameters of cloud and precipitation with both single-band and dual-band cloud radars.
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