| Cloud is an important meteorological element and has an important position in all fields of atmospheric science research.In the meteorological observation business on the ground,cloud-based observations mainly rely on manual labor.Manual observations have many drawbacks,are subjective,and cannot guarantee the reliability of the observations,and have low automation.Because the millimeter wave wavelength is close to the size of cloud particles,the high frequency millimeter wave cloud measurement Doppler effect is obvious,suitable for detecting cloud particles.Therefore,millimeter wave cloud radar is widely used in cloud physics and precipitation physics research.It has important application value and practical significance for the millimeter wave cloud measurement radar data processing and quality control research.This paper analyzes the base data of the millimeter wave cloud measuring radar,generates echo images,and designs a visual interface;analyzes the cloud measuring radar technology,proposes a data quality control algorithm based on cosine similarity,and solves the problem caused by the double frequency pulse compression technology Range side lobe and secondary echo problems;using the echo data of cloud measurement radar,the cloud macro-feature parameters are analyzed,and the algorithm of cloud macro-feature recognition based on fuzzy logic is proposed,which is compared with the manual observation experiment;The wind field simulation of cloud radar gives the wind field image distribution of millimeter wave cloud radar.The main research content and research results of the paper are as follows:(1)The millimeter-wave radar cloud-based radar data format and its components are analyzed.The radar-based data is subjected to binary decoding,numerical calculation,height correction,and coordinate conversion to generate radar echo images.Designed radar echo visualization interface,developed echo image display software,respectively realized the echo image reading in four formats of RHI,PPI,VOL and THI,which can be used for millimeter-wave radar meteorological observation,cloud physics and precipitation physics Research areas.(2)The cloud compression radar pulse compression technology and double pulse technology are analyzed separately,and the cosine similarity method to solve the problem of echo expansion and secondary echo is proposed.By processing radar echo data,if the similarity exceeds 50%,it is determined that there is a secondary echo.The problem of echo expansion is analyzed by examples,which shows that the method has good recognition effect.At the same time,the problems of attenuation correction and Mile scattering that need to be considered in data quality control are pointed out.(3)The general method of cloud recognition is studied,and the characteristic parameters of cloud recognition are analyzed.A cloud recognition algorithm based on fuzzy logic is proposed.The average intensity(Zave)of the reflectance factor,the direction of the long axis of the ellipse(?),and the height of the cloud base are selected.(CB)and other eight parameters are used as identification parameters of fuzzy logic algorithm and set different weights.Using the radar echo data of the observation station,the experimental verification is carried out,and the automatic recognition of the cloud shape is realized;and the experiment with artificial observation is carried out In contrast,the recognition accuracy rate exceeds 70%,which proves the effectiveness of the method.(4)The characteristics of the wind field based on RHI Doppler were analyzed,and the wind field was simulated under three scenarios,namely,constant wind direction,varying wind speed with altitude,constant wind speed,varying wind direction with altitude,and wind direction and wind speed varying with altitude.The image distribution of millimeter wave cloud radar RHI Doppler velocity shows that wind field inversion is also an aspect of cloud radar application. |
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