Research On Typhoon Winds And Waves Based On Satellite Remote Sensing And Numerical Simulation

The remote sensing satellite of synthetic aperture radar(SAR)in marine satellite remote sensing is an active microwave radar remote sensing satellite.It has the characteristics of all-weather,full-time and large area with high resolution.At present,the sea surface wind retrieval algorithm of co-polarization SAR images has been basically mature,but the backscatter cross section value of the co-polarization SAR images will reach saturation in retrieving high wind speed.It is found that the backscatter cross section value of cross-polarization SAR images.It is found that the backscatter cross section could keep increase as wind speed increases.Therefore,it is of great significance to develop a typhoon winds retrieval algorithm based on cross-polarization SAR images.In wave numerical simulation,the third generation wave numerical model WAVEWATCH-? has developed into one of the most mature wave numerical models in the world.It has more characteristics such as a variety of input and dissipation source terms,wave-wave interaction,wave-flow interaction and so on.Therefore,it is of great significance to use WAVEWATCH-? to predict of typhoon waves.This paper is divided into two parts.The first part mainly uses cross-polarization GF-3 SAR satellite remote sensing images to construct the cross-polarized SAR image typhoon winds retrieval algorithm.The second part mainly evaluates the effect of WAVEWATCH-? simulating the typhoon waves of the East China Sea.It also gives the best input and dissipation source terms.For the study on typhoon winds retrieved from cross-polarization GF-3 SAR images,these datasets were collected that 7 cross-polarized GF-3 SAR Remote Sensing Typhoon images and global and regional assimilation and forecasting systems(GRAPES-TYM)typhoon winds.The dependence between radar incident angle,wind speed over 10m/s and SAR image NRCS is explored.Then the function model of retrieval algorithm is constructed,and the coefficient is obtained by least square method.Next,the new algorithm is used to retrieve typhoon winds from cross-polarization SAR images,and the retrieval is compared with measurements from Wind-SAT grid winds.According to the comparison,the root-mean-square error and standard deviation are about 5.5 m/s.It proves the new algorithm has a capability to retrieve typhoon winds.In order to further verify the advantages of the new algorithm,it is compared with other four retrieval algorithm of C-band cross-polarization SAR images.The derived results are compared with GRAPES-TYM typhoon winds.The new algorithm shows the minimum root-mean-square error 5.11 m/s and the standard deviation 5.06 m/s.For the study on evaluating the effect of WAVEWATCH-? simulating the typhoon waves,WAVEWATCH-? is implemented to simulate typhoon waves by using 7 input and dissipation source terms provided by WAVEWATCH-? in East China Sea.First of all,c the Holland typhoon winds model is combined with European Centre for Medium-Range Weather Forecasts(ECMWF)which provides the 0.125° winds.The maximum method is used to construct H-E typhoon winds as the forced wind field of WAVEWATCH-?.Secondly,7 input and dissipation source terms provided by WAVEWATCH-? are used to simulate the significant wave height of the East China Sea during Typhoon "Fung-wong" and "Chan-hom".The comparison between simulations and measurements from in-suit buoys show that the simulations of ST2 source term are the best.The bias is 0m and 0.53 m and the mean square root is 0.79 m and 1.12 m during “Fung-wong” and “Chan-hom”,respectively,...