The Research Of Retrieval Algorithm Optimization For Wind Lidar Based On Iodine Filter

Wind lidar has become one of the most effective tools for measuring atmosphericwind field, and wind retrieval algorithms directly affects the accuracy andperformance of wind lidar. In order to improve the measurement accuracy of windfield, retrieval algorithm optimization is an important approach. For the Doppler lidarbased on iodine filter, on the basis of the original retrieval algorithm of wind profile,wind profile retrieval algorithm optimization is introduced and retrieval algorithm ofDual-Doppler lidar wind field is carried out.Firstly, composition of lidar system and spectrum of thebackscattered signal isintroduced; Secondly, principle of wind velocity measurement and wind profilerretrieval algorithm bydirect measuringsensitivity is introduced; Main parts of thethesis is retrieval algorithm optimization of wind profile and research on algorithm forDual-Doppler lidar horizontal wind field.There are three parts in retrieval algorithm optimization of wind profile: Firstly,affecting factors of sensitivity nonlinear errors are analyzed and errors in differentaerosol concentration and different height are compared, then error correction methodwith look-up table is introduced which is proved by synchronous data of wind lidarand radiosonde. RMSE (RootMeanSquare Error) of wind speed between radiosondeand wind lidar reduces from2.52m/s to2.31m/s, about8.33%. Secondly, aerosolconcentration should be taken into account when deriving wind profile from PPI dataof line-of-sight velocity (LOSV) by VAD algorithm.Aerosol extinction coefficient iscalculated with Fernald methodto control the quality of line-of-sight velocity. As aresult, measurement accuracy is improved under partly cloudy conditions.Finally,measurement accuracy of wind profile at low altitude is also improved by optimizingthe data merging algorithm forAD converting and photon counting data. Measurement accuracy of horizontal wind field can be improved byDual-Doppler lidar and research was carried out using LOSVPPI data of multipleelevations. Firstly, principle and method of Dual-Doppler lidar horizontal wind fieldmeasurements are introduced. Secondly, result of wind field is presented andanalyzed.In addition, data products were divided into three levels by the feature of windlidar data and requirementof wind field parameters, which is aimed to increaseefficiency of the data managementafterwards. Finally, research of lidar dataprocessing software is performed and the software based on MATLAB GUI isdeveloped.