全息地球数据立方体模型研究

Research on the Digital Holographic Earth Data Cube Model

进入地球大数据与地球人工智能时代,数字地球建模要求也从地表扩展到全域全时全息,而当前数字地球的数据模型还基本停留在瓦片或地球网格剖分数据模型阶段,严重制约了场景化、智能化数字地球应用。本文提出了全息地球概念以及相应的地球数据立方体组织模型,采用全球多级格网参考系统来描述和表达多尺度空间,用平面或立体格元来表达空间位置,将传统“经度、纬度、高程、时间”时空表达发展至“时间粒度、时间覆盖、网格位置、格网尺度”新时空表达体系,并设计了按照“时间—空间—尺度—属性”一致性描述的全息地球数据建模方案,将矢量、栅格、格网、时序阵列、三维模型等多模态数据归纳至一个统一模型中,使得任何引用特定地球数据立方体中的数据值在时间、空间、尺度都是对齐的,解决了全息地球跨专业、多维时空动态场景数据时空融合集成难题,并结合深时数字地球国际大科学计划全球数字化科研平台需求,开发了深时古地形时空动态可视化模拟系统,完成对模型的验证。

With the development of big data and artificial intelligence,the scope of digital earth modeling has extended to full-time holography beyond the earth surface.However,the current data model of digital earth still remains in the data modelling of earth tile or grid subdivision.This model severely limits the application of scenario-based and intelligent digital earth development.This paper proposes the concept of digital holographic earth and a corresponding data organization model of earth data cube.By using global multi-level grid reference system to describe and express multi-scale space and using two or three-dimensional grid cells to describe spatial positions,the traditional spatiotemporal description of"longitude,latitude,elevation,and time"is transformed to a new spatiotemporal description system of"time granularity,time coverage,grid position,and grid scale".The proposed model is characterized by the dimensions of"time-space-scale-attribute"based on spatiotemporal big data in the digital earth.The model encapsulates vectors,rasters,grids,time series arrays,and 3D models into an unified system.This unified system ensures that any data value of a specific earth data cube is aligned perfectly in time,space,and scale,which solves the problem of multi-dimensional or spatiotemporal dynamic fusion of big earth data.Finally,this paper develops a deep-time and spatiotemporal dynamic visualization simulation system to verify the data model based on the requirements of the Deep-time Digital Earth International Science Program.