| In the meteorologica l field,wind speed and wind direction are one of the most basic elements to observe.The traditional method is vulnerable to bad environment when working.The Doppler wind radar's high cost of the device makes it difficult to promote itself in the field of wind power.This thesis put forward a side-scattering Lidar based on CCD,researching the relationship model between radial wind speed and the total value of light intensity distribution,and verified it.After that,influence analysis is given.The detail in this thesis are as listed below:(1)The background of this research and several common methods of measuring speed of wind currently are introduced,and the structure,characteristics and history of lidar are described in detail.Meanwhile this chapter analyzes the current situation of lidar at home and abroad.(2)The related theoretical bases of research on speed of wind based on side-scattering lidar are introduced,including composition of atmospheric aerosols and the form of scattering.Furthermore,this chapter describes the Mie scattering theory of single spherical particle under the action of laser in detail.Finally the theories on detection of side-scattering lidar are introduced combined with its equation.(3)A new type of device to measure wind based on side-scattering lidar is proposed.According to the theory of side-scattering and the equation of side-scattering lidar,the linear relationship between the near-surface aerosol concentration and the total light intensity distribution of the side-scattering is verified.The detecting device collects the echo signal graph and extracts the light intensity information,and compares with the real-time speed of radia l wind value of the monitoring site to establish a relationship model between the total light intensity distribution value and the speed of radial wind.Through periodic analysis of the monitoring sites,it is determined that the aerosol concentration in the absence of wind is in the range of 50-60 ?g/m3,60-70 ?g/m3 and 70-80 ?g/m3 for three experimental grades.In order to overcome the interference caused by various factors such as wind direction and background interference light,the experiment chooses to use the wind speed controllable axial flow fan instead of natural wind to collect and analyze the data on clear and windless nights,and obtain preliminary conclusions and model of their relationship.(4)There lationship between the speed of radial wind and the total light intensity distribution obtained by the side-scattering lidar measurement system based on CCD is verifie d by multi-directional experiments based on the real-time wind direction on good nights.Then,based on the side-scattering lidar,the experiment on different environmental conditions is carried out,and the influence of vertical height and temperature on the measurement results of the relationship between radial speed of wind and the total light intensity distribution is analyzed,so as to improve the accuracy of the data model in the subsequent wind condition research process.Further improve the accuracy of the developed side-scattering lidar system.Based on the quantitative analysis of the data obtained at the monitoring point in the whole experimental period,it is preliminarily concluded that when the wind speed is in the range of 0~4 m/s,the total light intensity distribution of the side-scattering lidar increases with the increase of the radial speed of wind,and when the wind speed is kept above 5 m/s,the total light intensity distribution of the lidar decreases with the increase of the radial speed of wind.There lationshipl between the total light intensity distribution and radial speed of wind in the he ight range studied in this chapter(0~40m) gradually decreases with the increase of height;by comparing the relationship between radial speed of wind and the total light intensity distribution in different months,it is concluded that the relationship between the total light intensity distribution of side-scattering and the radial speed of wind gradually decreases with the increase of temperature. |
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