Research On Aircraft Wake Vortex Recognition Based On Coherent Doppler Lidar

The wake vortex of the aircraft will affect the safety of the following aircr aft due to its long duration and severe disturbance.In order to avoid the impact of the wake vortex of the preceding flight,airport air traffic controllers usually adjust the take-off interval between flights based on experience.In order to break through the limitations of this empirical judgment and consider the evolution of wake vortices affected by turbulence,it was proposed to use coherent doppler wind lidar to detect aircraft wake vortices in real time,and an automatic recognition method for aircraft wake vortices was proposed.The reference provided by airport controllers is of great significance in improving the efficiency of airport control.Coherent doppler wind lidar,as an effective means of detecting the clear sky atmospheric wind field with high time resolution and high speed resolution,plays a good role in the detection of aircraft wake vortices.In order to realize the automatic recognition of aircraft wake vortices,based on the processing of the actual measurement data of coherent doppler wind lidar to detect aircraft wake vortices,from the perspective of constructing a two-dimensional wind field vector,a wake vortex recognition method is proposed and evaluated.This method is better for vortices deformed by turbulence,and provides an important reference for identifying wake vortices on the basis of turbulence.In order to propose an effective identification method,the characteristics of the aircraft wake vortex were analyzed.The wake vortex characteristics were analyzed from the formation,dissipation and the entire evolution process of the wake.Among them,the characteristic parameters describing the wake vortex characteristics were proposed to further extract features of the wake vortex for reference.At the same time,the system,working principle and data output of the coherent doppler wind lidar were explored,to study the detection of the wake vortex by the coherent doppler wind lidar.The wake vortex data in the radar output wind field was preprocessed and visualized.Based on the analysis of wake vortex characteristics and radar detection data,it provides a reference for the subsequent realization of wake vortex identification.According to the wind field data output by the coherent doppler wind lidar and combined with the wake characteristics,a method was proposed to construct a two-dimensional wind field vector using the assumption of uniformity.In the method,the wind speed component was estimated to obtain the two-dimensional wake vortex vector distribution of the wind field;it was proposed to use two scalar functions to identify the vortex center and boundary on the basis of the constructed two-dimensional wind field vector to realize the identification of the wake vortex under the influence of turbulence.And finally analyzed the wind field spectral width data of the aircraft wake vortex case,the wake vortex spectral width data results obtained in the typical case were compared with the recognition results of the proposed recognition method,and further realized the evaluation of the wake vortex recognition method.