Digital Bathymetric Model Construction Of East Indian Ocean Based On Multi-source Bathymetric Data Fusion

Carrying out the fusion of ocean multi-source bathymetric data and construct its high-precision digital bathymetric model is of great significance to ocean bottom scientific research,deep sea resource development and protection.The current global ocean bathymetric data,due to the difference in measurement period,measurement method,bathymetric and positioning accuracy,have produced multi-source complexity,which has caused uncertainty in the description of seabed geospatial information,which is not conducive to the application of ocean seabed topographic data.This paper selects a part of the ninety east ridge in the northern part of the East Indian Ocean as the research object,studies the fusion method of multi-source bathymetric data and constructs a digital bathymetric model of the sea area.The main work and innovations are as follows:1.This paper first sorts out the research data sources such as multi-beam bathymetric data,single-beam bathymetric data and general bathymetric chart of the oceans(GEBCO),and expounds the processing process of multi-beam data and the accuracy evaluation method of bathymetric data,and carries out the accuracy evaluation and least squares correction of data in the research area.2.According to the characteristics of the bathymetric data in the East Indian Ocean,based on the summary and analysis of the commonly used digital bathymetric model construction methods,a variational fusion method is proposed to construct the digital bathymetric model based on multi-source bathymetric data fusion.The final digital bathymetric model not only retains the detailed information of high-precision bathymetric data,but also provides a smooth terrain surface for the data blank area.The resolution of the model generated by fusion in this study is 100m,which is also the highest accuracy digital bathymetric model in the East Indian Ocean so far.3.The accuracy of the digital bathymetric model is evaluated,and analysis shows that the standard deviation of the digital bathymetric model is 27.68m.At the same time,the terrain factors of the seabed topography in the research area was carried out,calculated and extracted its slope and aspect,terrain relief,surface cutting depth,surface roughness,elevation variation coefficient,etc.,normalized the terrain factors and calculated its comprehensive terrain complexity index of the research area,and finally obtained that the ninety east ridge region has the highest comprehensive terrain complexity,with an index of 0.039,and the terrain fluctuates greatly.The comprehensive complexity index of the west area is 0.020.Except for some banding phenomena and seamounts,the overall topography is flat.The east area has the lowest comprehensive terrain complexity,with an index of 0.013.The overall seabed topography of the east area is flat except seamounts.Some of the research results of this paper have been applied to a national major special project.