Study On Optimization Of Data Processing And Application Of The Coherent LIDAR

Coherent Doppler lidar is often known for its high spatial and temporal resolution, fast response, and ability to adapt to bad weather such as rain and dust. As a new method of measuring wind field in recent years, it has a wide range of applications, especially in the wind power industry, the demand for wind radar is imminent. In this paper, the wind field is measured based on Coherent Doppler lidar and the data processing method is optimized. Coherent Doppler lidar is applied in the arid area, continuous rainfall weather and conducted a preliminary study for the haze process. The main innovations are as follows:(1) By using the method of fast Fourier transform and center of gravity method,the algorithm of extracting the line of sight velocity and horizontal wind field are completed. Carry out several observational tests and statistical analysis of lidar data,according to data processing and preprocessing methods, to solve the problem of background noise by atmospheric disturbances.(2) In this paper, we propose a method of constant false alarm rate detection for the short board under the condition of fast Fourier transform data inversion under the condition of SNR. The experimental data of 5 months in 2016 were analyzed and compared with commercial radar. Based on the natural conditions of low SNR, the feasibility of the optimization of lidar processing method is verified. The result of spectrum analysis of high consistency at high SNR; line of sight wind speed using the modified method at low SNR accords with the rule of atmospheric horizontal wind; The correlation of horizontal wind speed was 0.9966, which was increased by more than 11.49%; mean absolute deviation of the horizontal wind direction is 1.9382 degrees, the correlation coefficient was 0.9986, the correlation is improved by 0.0087. At the same time, the error statistics are given.(3) Under the condition of drought, sandstorm and precipitation, the coherent lidar is used to test together with one 150m wind tower and one commercial radar.The experimental results show that the coherent lidar can adapt to the harsh environment, and can be as good as the commercial lidar and the wind tower. The use of coherent Doppler lidar to detect the winter fog and haze in Nanjing, concluded that in the fog and haze weather, the daily variation in the distribution of aerosols is larger, the duration of severe fog and haze weather is not long.