Research On Automatic Gust Front Recognition And Its Application In Xi'an Xianyang Airport

As a king of severe weather,gust fronts can often lead to property damage,casualties,and fatal threats to aviation.The research of gust front and automatic identification is not only a scientific issue,but also the basis of related disaster prevention and reduction.Therefore related research has important theoretical significance and application value.At present,there are many researches on the theory of gust front automatic identification and early warning,but there are relatively few researches on practical applications.Therefore,this study uses Xi’an Doppler radar observation data,NCEP reanalysis data,and automatic weather station data from June to August 2016 to analyze the statistical analysis of the gust front in Xi’an Xianyang Airport,the realization of the identification process,the results verification,the interface design,and the functions implementation.The main results are as follows:(1)The gust front echo statistical features are generally intensity 5-15 dBz,width2-4km,length 30-50 km,vertical height 1-2km.The gust front moving direction is more northwest-southeast direction,generally occurs at 1.5° elevation angle.The convergence of the wind field appears near the gust front.(2)Based on file monitoring,decompression,decoding,display,and other c# key technologies,the radar data is subjected to processing such as orphans,isolated dot lines,echo flatness,noise filtering,missing-test padding,and median processing.The echo is used for data classification,bidirectional gradient generation,refinement,short-term filtering,and linked list recognition to realize recognition.The radial velocity is subjected to steps such as shear parameters,velocity gradient,momentum,and merging to realize identification.The successful detection rate of the reflectance is 80.5%,the highest is 93%,the lowest is 43%,and the average detection rate is 77%.The detection rate of radial speed is 52.6%,the highest is73%,the lowest is 13% and the average recognition rate is 49.3%.Overall,narrow-band echo are better than convergence line,so the recognition effect is better.(3)On June 4,2016,with the Mongolian eddies,a torrential precipitation and windy weather appeared over the Xianyang Airport when the gust front crossed the airport.The characteristics of the gust front on the radar echoes are short-life,long horizontal scale,fast speed,accompanied by obvious narrowband echo and convergence line.The designed software can automatically identify the gust front location,length,distance.POD was 93.75% and the critical success index was83.33%,indicating that the software was effective for identification of gust front at Xianyang Airport.(4)The interface design of gust front automatic identification and early warning software was introduced at Xi’an Xianyang Airport.This study designed and analyzed the process of automatic identification,confirmed the specific functions of the software,and the software interface area was divided into four parts.The design and function of the two main parts of menu bar and the display area were introduced.Finally,the realization process of the automatic identification and early warning and the key classes and functions cited are verified,which verifies that the software automatic identification algorithm is accurate and feasible,and meets the actual application.