Study On Echo Recognition Algorithms Of Severe Weather Based On Weather Radar

Doppler Weather Radar with the higher time and space resolution become one of the main tools in monitoring and warning severe weather. Doppler Weather Radar can provide us three basic products such as reflectivity, velocity and spectrum width. We can obtain other derivative products after algorithm introduced. The accuracy of product depends on the production algorithms and quality of base-data.As the application in operation of WSR-88D radar, there are many algorithms set up in the echo recognition, of severe weather. Our scholars also research the echo recognition to be localization of it. But basically just some one of severe weather is researched separately. In the article several kinds of severe weather echoes can be recognized together, which is complete and new.We have analyzed the Radar products of severe storms in Jiangsu and Anhui provinces, and show that:1、we choose Doppler radar echo intensity、echo top、top of45dBZ echo intensity、 VIL and VILD to form equation to distinguish Hailstorm, which is appropriate.2、The change of height of Centroid of mass in6minutes and the velocity divergence in one-dimensional are important factors to distinguish Downburst.3、It is accurate to use the data of rain gauges to calibration rainfall intensity obtained from radar data.The algorithm is applied to recognize the echoes in July25th in2007, when there are hailstorm, thunderstorm and so on. The results show the hailstorm and downburst can be recognized and warning time is about6～12minutes.