Positioning Research Of Typhoon Center Based On Satellite Images And Microwave Scatterometer

Typhoon is a strong atmospheric vortex on the tropical ocean,and it both expressed as an organized feature of vortex in satellite cloud image and scatterometer wind field data.China is located in the Western Pacific Ocean where is one of the most serious influenced areas affected by typhoon every year.It is a very important to identify typhoon center accurately for monitoring and forecasting typhoons.Positioning typhoon center is one of the key technologies of typhoon analysis business.Owning to the complexity of typhoon form and movement,positioning typhoon center is still in the stage of research and exploration until now.On the home and abroad existing researches basis,the paper attempts to use the satellite cloud image and microwave scatterometer data to study the typhoon center positioning and related issues in-depth,the specific contents as bellows:1.Based on the visible light,infrared cloud images of FY-2 and microwave scatterometer wind field data of HY-2,a variety of typhoon center positioning methods are analyzed and studied.The “spiral-ring center” typhoon center positioning method based on satellite cloud image of FY-2,the “regional wind speed method” and the “regional wind direction method” typhoon center location method are proposed through microwave scatterometer of HY-2.It performed some experiments each positioning method,the results are compared with the National Meteorological Administration(CMA),the Japan Meteorological Agency(JMA)and the Joint Typhoon Warning Center(JTWC)optimal track data for comparative analysis,select Great Circle Distance(GCD)method for the accuracy of the experimental evaluation,the results are as follows:Typhoon “ChanHom” microwave scatterometer typhoon center location and monitoring track and CMA,JMA,JTWC GCD are 63.45,55.61,65.66.The standard deviation is 31.74,48.54,55.56;Typhoon “Soudelor” microwave scatterometer typhoon center location and monitoring track and CMA,JMA,JTWC GCD are 47.29,53.45,59.87.The standard deviation is 73.93?89.77,91.17;Typhoon “Dujuan” microwave scatterometer typhoon center location and monitoring track and CMA,JMA,JTWC GCD are 60.78,45.66,57.88.The standard deviation is 44.37,41.71,58.69.2.Based on the above-mentioned different typhoon center location methods,it utilized linear and non-linear regression method to analyze the mathematical relationship between satellite cloud image and microwave scatterometer,through a large number of experimental analyses,and optimal fitting of the independent variable and the dependent variable relationship.Then used the satellite cloud image and its derived quantity to find the optimal fitting function,established the mathematical model satellite cloud image of of FY-2 and microwave scatterometer data of HY-2,and finally got the fitting data.During the period without microwave scatterometer data to monitor and forecast typhoons,it used the data to locate typhoon center and accurate the evaluation.The results showed that the location of the typhoon center is better than microwave scatterometer data identified.The results are as follows:Compared with the microwave scatterometer typhoon center location and monitoring track,the GCD typhoon “ChanHom” are respectively improved 9.86,0.91 and 9.07;Compared with the microwave scatterometer typhoon center location and monitoring track,the GCD typhoon “Soudelor” are respectively improved 0.59,5.16 and 9.28;Compared with the microwave scatterometer typhoon center location and monitoring track,the GCD typhoon “Dujuan” are respectively improved 4.38,0.91 and 6.82.The above research shows that the method of fitting the satellite cloud image,the microwave scatterometer typhoon center location,and the effect of typhoon center location,compared with the microwave scatterometer typhoon center location data,it is more intensive in the time series of typhoon monitoring than the microwave scatterometer wind field.