Study On Estimation Method Of Sea Surface Wind Speed Based On Multi-angle Sun Glitter Images

The sun glitter is caused by the direct reflection of the sun light from the sea surface.In detecting the characteristics of the ocean,the sun glitter is considered to be a serious loss of data in the study of conventional ocean optical images,and it will become noise,and the accuracy of ocean information extracted by interference.But at the same time,because the sun glitter information contains abundant sea surface roughness information,the sun glitter images can also be used to detect many marine dynamic processes and phenomena,such as ship wakes,ocean internal waves,oil traces,submarine sand waves and sea surface wind field,etc.This paper revolves around the multi-angle sun glitter images and theirs application in the estimation of sea surface wind speed,based on the geometric model of multi-angle sun glitter imaging,the sun glitter radiance transfer model and the probability density function of wave slopes.The estimation method of sea surface roughness and sea surface wind speed based on multi-angle sun glitter images are studied.The contents and results of this paper are as follows:In this paper,the imaging principle of sun glitter images is discussed,and the imaging geometry relation of multi-angle images is discussed.Based on the geometric model of sun glitter images and the calculation method of geometric parameters of multi-angle sun glitter images,and the geometric parameters of the multi-angle sun glitter images are calculated by each pixel,which provides the basic parameters for the subsequent estimation of sea surface roughness and sea surface wind speed.In this paper,the characteristics of the Multi-angle Imaging Spectro Radiometer(MISR)are discussed,the reading method of MISR data is introduced,the scope of the research area is selected,the general situation of the research area is analyzed,and the longitude,the latitude and the imaging time needed for subsequent calculation are extracted from the original data.Based on the multi-angle sun glitter remote sensing model,this paper introduces the probability density function model of the inclined sea surface,it is called the CM model,and obtains the estimation model of the sea surface roughness based on the multi-angle sun glitter images of MISR.Based on the quantitative relationship between the sea surface roughness and the wind speed of the CM model,the estimation of the sea surface wind speed from the sea surface roughness is realized.The mechanism of estimating sea surface wind speed by multi-angle sun glitter images is further understood,which provides a basis for the selection and analysis of multi-angle s sun glitter remote sensing images.Based on the wind speed data of European Centre for Medium-Range Weather Forecasts and buoy wind speed data,the application examples of this model are verified and evaluated.The experimental results show that there is good correlation with ECMWF wind speed(R=0.745),the root mean square error is 1.514 m/s,and the average absolute error is 1.319 m/s.The accuracy of wind speed inversion is higher than that of scatterometer and SAR.Therefore,this method extends the application of multi-angle MISR sun glitter images information,lays the foundation for multi-angle sun glitter images to estimate sea surface wind speed,and is a new idea of sea surface wind speed detection.