Feature Extraction Method Of Global Ocean Current Field Based On Hexagonal Discrete Grid

The ocean is not only the basic space for human survival,but also an important stage for international political struggles.Important ocean phenomena such as tidal phenomena,ocean flow field motions,and eddies have always been the hotspots of research by scholars at home and abroad.At present,most scholars' research on the ocean is based on the latitude and longitude grid,but the shape of the latitude and longitude grid will gradually deform as the latitude rises,and the grid cells at the north and south poles will even degenerate into triangles;This grid does not consider the density and size of spatial data,which in turn will affect the accuracy of the data calculation results.And a new multi-resolution data fusion and geo-simulation solution for the whole world,the global discrete grid,is a new global spatial data integration and analysis method proposed for the defects of the latitude and longitude grid.Therefore,this article plans to perform calculations in a global discrete grid to improve the accuracy of the results.This article summarizes the existing extraction of ocean tide harmonic constants,ocean current field calculations,and ocean vortex feature region extraction,and based on the existing global discrete grid research results,in the global icosahedral hexagon discrete grid.The calculation method based on the hexagonal global discrete grid is proposed under the framework of the grid.The research content and results of this article mainly include:(1)A method for extracting harmonic constants of ocean tides based on a hexagonal global discrete grid.Interpolate the satellite altimetry data into a grid,calculate the astronomical initial phase angle and other related parameters in a hexagonal discrete grid,then use these parameters to calculate the tidal harmonic constant,and finally compare the calculated results with the actual observation data.Experimental results indicate that this method can extract marine tidal harmonic constant in a hexagonal discrete grid.The accuracy of the results obtained is not significantly higher than that of the latitude and longitude grid in the far coast sea area,but it is improved in the near coast sea area.(2)The calculation method of ocean current field based on the hexagonal global discrete grid.Calculate global ocean surface geostrophic currents and Ekman currents in a hexagonal discrete grid using sea level data and sea surface wind field data,and combine the two to obtain global ocean surface currents.Finally,the calculation results are combined with actual ocean current observation data Make comparisons to verify the accuracy of the results.Experimental illustrate indicate that this method can calculate ocean surface flow field data in a hexagonal discrete grid.The accuracy of the results obtained is not significantly higher than that of the latitude and longitude grid in the middle latitudes,while the accuracy in the low and high latitudes is equal.Has been improved.(3)Extraction method of ocean vortex characteristic region based on hexagonal global discrete grid.In the hexagonal discrete grid,the velocity data is first interpolated.After the center of the vortex is extracted by Sperner's lemma,the vortex range is obtained by the vortex region boundary extraction method based on field growth,and finally the obtained The result is compared with the authoritative vortex data set to verify its accuracy.The experimental results indicate that the method can complete the extraction of ocean vortex characteristic regions in a hexagonal discrete grid.Compared with the calculation results of the latitude and longitude grid,the obtained vortex results are accurate in the number of successful vortex extractions and the vortex range.The degree has been improved to a certain extent.This experiment verifies to a certain extent the advantages of the hexagonal discrete grid over the latitude and longitude grid,and provides an effective data source and algorithm reference for the calculation of ocean data models under the global hexagonal discrete grid.