| Millimeter-wave cloud radar is a meteorological remote sensing device,It is mainly used for constantly detect the vertical structure of the cloud.Compared to conventional weather radar,millimeter-wave cloud radar has obvious advantage in detecting small particles,and has high velocity resolution and temporal-spatial resolution.At present some domestic institution have been developed 35 GHz millimeter-wave cloud radar and put into operation,94 GHz millimeter-wave cloud radar is also in development.Millimeter-wave cloud radar can not only detect cloud,but also have the ability to detect precipitation,and has certain advantage in detecting weak precipitation.However,the millimeter-wave is easily affected by the attenuation caused by precipitation particles;the rain attenuation leads echo intensity decreases and influence the accuracy of observation data.This paper firstly introduces the development and present situation,measuring principle,echo characteristics,performance of millimeter-wave cloud radar and wind profiler,and particularly expatiate the radars,data used in the study,radar signal processing procedure,data quality control process,and power spectrum processing method.Millimeter-wave cloud radar is mainly used to detect the vertical structure of clouds,and has the ability to observe weak rainfall,and wind profiler has both the ability to detect precipitation particles and atmospheric turbulence.According to the characteristics of these two radars,this paper research the attenuation characteristics of millimeter-wave cloud radar's power spectrum and try to correct them with a wind profiler,then extract turbulence spectrum of wind profiler in precipitation.The data are mainly got in stratified precipitation in this study,through statistical and analysis,it is found that attenuation has a linear relationship with the falling velocity of precipitation particles,the modified power spectrum of millimeter-wave cloud radar is used to extract the turbulence spectrum from the power spectrum of wind profiler,and it has achieved some effects.At the same time,the applied range of wind profiler is also extended under some condition.In the study,the millimeter-wave cloud radar is installed near the wind profiler and is used to observe precipitation and get the power spectrum of precipitation particle.Due to the serious attenuation of millimeter-wave in precipitation and scattering mechanism of precipitation particles for different radar wave is different,these will result in difference on radar power spectrum.This paper correct the power spectrum of millimeter-wave cloud radar from scattering and attenuation,then the corrected power spectrum are used to extract turbulence spectrum.We extract turbulence spectrum from more than 2200 power spectrum of wind profiler,under stratified precipitation with low precipitation intensity,and millimeter-wave can penetrate the precipitation,the test results are divided into three categories according to the correction and extraction effect,61% for good effect,28% for general effect and 11% for poor effects.It is indicates that the revised power spectrum of millimeter-wave cloud radar can be used to extract turbulence spectrum of wind profiler in most cases. |
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