Research On Data Management And Three-dimensional Visualization Technology For Global Marine Reanalysis Data

With the development of marine exploration instruments,scientific research institutions have accumulated a large amount of marine data.By transforming complex and abstract data into vivid and concrete images,data visualization technology enables the marine environmental factor data to intuitively show the morphological distribution characteristics of the marine environmental factor field,improves the research and utilization ability of marine data,and is of great significance to the further study of marine science.Due to the increasing size of marine data and the large differences in data formats and types,it is extremely important to manage massive marine environmental factor data uniformly and realize efficient three-dimensional visualization.Therefore,this paper studies a variety of three-dimensional visualization technologies.A three-dimensional data coding and management scheme is designed according to the characteristics of data sets.Three-dimensional visualization of marine environmental data is realized based on Ray-Casting algorithm.Aiming at the shortcoming of this algorithm,an optimization scheme is proposed.A three-dimensional visualization software system of marine environmental factor field is designed and developed.First of all,the characteristics of the original data are analyzed,and a three-dimensional data encoding and storage method for data extraction is designed aiming at the characteristics of large redundant data sets.The original data is analyzed and subdivided to extract four basic marine environmental factor data sets.The three-dimensional data encoding scheme is designed to unify the longitude,latitude and depth of the data of marine environmental factors into a set of coding,so as to reduce data redundancy and facilitate the rapid positioning of the marine spatial location.By taking three-dimensional coding reflecting spatial location information as the index number and various environmental factor data as attribute values,the database table structure is designed to achieve accurate positioning and rapid extraction of required data and efficiently manage massive data.Secondly,through the analysis and research of relevant algorithms of three-dimensional data visualization,the advantages and disadvantages of each algorithm are compared and summarized.Combined with the data characteristics of marine environmental factors,Ray-Casting algorithm is selected as the realization algorithm of visual rendering,and its basic principle and calculation process are mainly studied to lay a foundation for its application for the visualization of marine environmental factors field.According to the characteristics of data of marine environmental factors,three-dimensional visualization is realized by using Ray-Casting algorithm.Thirdly,the deficiencies of Ray-Casting algorithm in the visualization application of marine environmental factor data are analyzed.Aiming at the image distortion problem caused by non-uniform data,the interpolation algorithm is used to carry out data homogenization processing in the depth direction of three-dimensional field.Aiming at the calculation error problem of mixed elements in the resampling link,a new calculation method of sampling points is proposed and improved the resampling efficiency by combining the method of automatically adjusting sampling step.To solve the problem of low efficiency in image synthesis,an appropriate cumulative opacity threshold is designed to terminate the process of light projection synthesis in advance.Through a large number of comparative experiments,it is verified that the improved scheme has a good optimization effect on the visualization of marine environmental factor data.Finally,on the basis of the research on the theory and technology of three-dimensional visualization of marine environmental factor data,the software system is designed and developed.The software system mainly includes the realization function of multi-element and multi-category visualization and the statistics and query function of target data to meet the requirement of man-machine interaction.