SolidEarth： a new Digital Earth system for the modeling and visualization of the whole Earth space

Although many of the first-generation Digital Earth systems have proven to be quite useful for the modeling and visualization of geospatial objects relevant to the Earth＇s surface and near-surface, they were not designed for the purpose of modeling and application in geological or atmospheric space. There is a pressing need for a new Digital Earth system that can process geospatial information with full dimensionality. In this paper, we present a new Digital Earth system, termed SolidEarth, as an alternative virtual globe for the modeling and visualization of the whole Earth space including its surface, interior, and exterior space. SolidEarth consists of four functional components： modeling in geographical space, modeling in geological space, modeling in atmo- spheric space, and, integrated visualization and analysis. SolidEarth has a comprehensive treatment to the third spatial dimension and a series of sophisticated 3D spatial analysis functions. Therefore, it is well-suited to the volumetric representation and visual analysis of the inner/ outer spheres in Earth space. SolidEarth can be used in a number of fields such as geoscience research and education, the construction of Digital Earth applications, and other professional practices of Earth science.

Interactive data styling and multifocal visualization for a multigrid web-based Digital Earth

Globe-based Digital Earth(DE)is a promising system that uses 3D models of the Earth for integration,organization,processing,and visualization of vast multiscale geospatial datasets.The growing size and scale of geospatial datasets present significant obstacles to interactive viewing and meaningful visualizations of these DE systems.To address these challenges,we present a novel web-based multiresolution DE system using a hierarchical discretization of the globe on both server and client sides.The presented web-based system makes use of a novel data encoding technique for rendering large multiscale geospatial datasets,with the additional capability of displaying multiple simultaneous viewpoints.Only the data needed for the current views and scales are encoded and processed.We leverage the power of GPU acceleration on the client-side to perform real-time data rendering and dynamic styling.Efficient rendering of multiple views allows us to support multilevel focus+context visualization,an effective approach to navigate through large multiscale global datasets.The client–server interaction as well as the data encoding,rendering,styling,and visualization techniques utilized by our presented system contribute toward making DE more accessible and informative.

Using modular 3D digital earth applications based on point clouds for the study of complex sites

This article discusses the use of 3D technologies in digital earth applications(DEAs)to study complex sites.These are large areas containing objects with heterogeneous shapes and semantic information.The study proposes that DEAs should be modular,have multi-tier architectures,and be developed as Free and Open Source Software if possible.In DEAs requiring high reliability in the 3D measurements,point clouds are proposed as basis for the 3D Digital digital earth representation.For the development of DEAs,we propose to follow a workflow with four components:data acquisition and processing,data management,data analysis and data visualization.For every component,technological challenges of using 3D technologies are identified and solutions applied for a case study are presented.The case study is a modular 3D DEA developed for the archaeological project Mapping the Via Appia.The 3D DEA allows archaeologists to virtually analyze a complex study area.

Augmented virtual environment: fusion of real-time video and 3D models in the digital earth system

An Augmented virtual environment(AVE)is concerned with the fusion of real-time video with 3D models or scenes so as to augment the virtual environment.In this paper,a new approach to establish an AVE with a wide field of view is proposed,including real-time video projection,multiple video texture fusion and 3D visualization of moving objects.A new diagonally weighted algorithm is proposed to smooth the apparent gaps within the overlapping area between the two adjacent videos.A visualization method for the location and trajectory of a moving virtual object is proposed to display the moving object and its trajectory in the 3D virtual environment.The experimental results showed that the proposed set of algorithms are able to fuse multiple real-time videos with 3D models efficiently,and the experiment runs a 3D scene containing two million triangles and six real-time videos at around 55 frames per second on a laptop with 1GB of graphics card memory.In addition,a realistic AVE with a wide field of view was created based on the Digital Earth Science Platform by fusing three videos with a complex indoor virtual scene,visualizing a moving object and drawing its trajectory in the real time.

Constructing a core framework of visual engine for Digital Earth system

A visual engine is the core of a Digital Earth system.There is a wide variety of functional requirements in Digital Earth system and different requirements correspond to different operations.Based on the development of the visual engine for ChinaStar,a 3D Digital China prototype software platform,and analysis of 3D Digital Earth platforms such as Google Earth,Virtual Earth,Skyline,etc,are discussed.A common core framework for a visual engine is proposed in this paper to construct a visual engine and then with this framework various Digital Earth application systems can be developed efficient.The parametric model of the Earth,scheduling and optimization in visual field,choice of 3D graphics library,and designing component-based visual engine framework of Digital Earth are discussed in detail.In addition,the relationships among these four basic components and the construction of visualization applications of Digital Earth by this method are also discussed.

在Google Earth平台上的虚拟社区构建

介绍虚拟现实技术及其在GIS中的应用,并采用Google Earth作为平台,利用已有数据资料进行虚拟社区的构建,并借助Google Earth进行发布,初步实现了相关功能,在一定程度上实现了虚拟现实技术与传统地理信息的结合。

Google Earth三维可视化在滇藏铁路林芝-拉萨段地质选线中的应用

以滇藏铁路林芝-拉萨段为例,利用Google Earth对两拟选线路方案沿线的活动断裂,滑坡、泥石流、崩塌等地质灾害进行遥感解译,并制作三维飞行动画。研究发现北线方案主要受泥石流影响,南线方案活动断裂、滑坡、崩塌、泥石流均较发育,从工程地质条件来看北线优于南线。

地球家园的生动记录：可视地球数字图书馆（Visible Earth）

作为美国宇航局（NASA）资助的数字图书馆项目之一，“可视地球”（Visible Earth）．数字图书馆旨在免费向公众提供有关地球科学的图像、动画以及其他的可视化信息，该馆面向学生、教育工作者、科学家、商业人士等，为用户提供了五彩缤纷的可视化地球资源。文章从资源组织、服务特征、技术特征等方面对VE做了概要评述，同时给出了笔者的评价与建议。

From Physical Space to Visual Image Space

The theoretical framework of visual simulation in virtual reality is discussed. The new concept of visual image space is supposed. On the basis of visual image space, in visual perceptive sense, VR is considered as a spatial simulation. The objective of the spatial simulation is to transform physical space to visual image space. Last, the prototype system, surveying & mapping virtual Reality (SMVR), is developed, and the space simulation above is realized. By use of SMVR, the real 3D representation, 3D visual analysis, virtual plan and designs can be implemented.

河口海岸数字孪生建设与挑战(特邀)

河口海岸是人类生存的重要空间和经济发展的关键区域。然而,在气候变化和人类活动的双重压力下,河口海岸面临环境恶化、湿地生态受损和灾害风险增加等多重问题。为保障河口海岸可持续发展,本文以数字孪生概念为基础,结合河口海岸多圈层多界面的系统特征,提出了一个综合河口海岸立体监测和数据聚融、多过程耦合模型系统、数字孪生体和智能服务平台等关键要素的河口海岸数字孪生系统。此外,本文还详细介绍了构建河口海岸数字孪生系统所需的核心技术,涵盖监测物联网、模型耦合、大数据管理和智能分析,以及知识图谱等。尽管面临多学科全要素综合监测、人地海耦合模拟、跨领域跨行业协同、信息安全保障和服务标准制定等多重挑战,河口海岸数字孪生具有逼近真实、系统关联和提供智能服务等特点,能够提供监测、预报、预警、预演和预案等智能服务。这将有助于提高我们对河口海岸复杂系统演变、预测和应对的研究和应用能力,推动河口海岸学科群的发展,提升风险管理和综合治理水平,为河口海岸可持续发展提供强有力的支持。

基于数字孪生的离子型稀土矿水冶工艺数据动态可视化研究

利用数字孪生技术为支撑体系,以离子型稀土矿水冶车间生产过程产生的实时海量数据资源分析、数据可视化、设备传感器、数据优化分析为核心,统筹工艺流程数字化赋能理念。将离子型稀土矿水冶车间数据动态可视化以“一张图”的方式呈现,构建离子型稀土矿水冶车间各工序数字孪生体,实现水冶时空动态监测,融合浸采、除杂、沉淀、压滤四大生产流程,打通多节点数据通道,支持智慧水冶车间数据汇聚共享,提供全方位、多种类立体数据监测信息,从而更好地支撑离子型稀土矿水冶车间管理工作,提高设备利用率和生产效率,降低成本,优化产能,提升智能化决策水平。

面向地球表面三维空间的远程监视覆盖优化

对地球表面三维空间进行远程监视覆盖有利于早期发现入侵目标。构建了地球表面曲率影响下的三维目标空间模型以及传感器三维感知模型,提出了覆盖优化算法。该算法将地球表面三维目标空间离散化处理,利用地(海)面固定位置三维有向传感器网络对目标空间感知监视,采用智能优化算法优化调整三维有向传感器主感知方向的方位角和俯仰角,从而最大化传感器网络对目标空间的监视覆盖率。

基于数字地球的洪水淹没分析及仿真研究

针对洪涝灾害中洪水淹没问题,采用现代信息技术对洪水进行淹没分析和三维仿真。基于瓦片金字塔模型生成研究区域的三维地形,在此基础上按照精度要求构建指定步长的矩形格网模型,对给定洪水水位值和洪水量已知的两种情况分别进行洪水淹没分析,提出洪水淹没仿真系统体系,采用三维仿真技术对洪水淹没进行三维仿真进行淹没过程的三维仿真。实例表明,方法具有较好的实用性,对防洪决策及洪灾后评估等具有重要意义。

关于构建矿山三维GIS的思考

根据煤矿生产的实际情况 ,分析了建立煤矿三维GIS的必要性 ,并针对当前GIS发展的状况 ,提出了建立矿山三维GIS的思路。

基于三维地球的多源空间科学数据可视化管理系统的设计与实现

如何高效地组织和管理日益增长的多源海量空间科学数据、提高数据的可用性和易用性,是空间科学目前需要重点解决的技术问题。在充分分析现有空间科学数据管理技术和数据特点的基础上,提出了一种有效的系统架构,研究并利用空间关系数据库及分布式数据库技术,实现了海量异构数据的高效存储、检索与定位;研究基于三维数字地球的多层次细节展示方法、三维数据剪裁、多线程并行加载等关键技术,提高了空间科学数据的集成可视化显示与应用效率。最后设计并集成了多源空间科学数据可视化组织与管理系统,在实际工程应用中验证了设计的合理性与有效性。

基于数字地球平台的地质钻孔三维模拟与可视化

研究了地质钻孔信息的管理和可视化技术,提出了一种在数字地球平台中进行城市钻孔信息模拟和可视化的方法。该方法基于一个统一的钻孔数据库标准,首先将钻探点位信息和地层分层信息组织成具有不同细节层次的钻探点位模型、钻孔分层散点模型和钻孔管段模型,然后构建基于细节层次模型的海量钻孔信息多尺度表达机制,最后将这些模型加载到数字地球平台中进行可视化及查询、分析。在上海市的应用实例显示,该方法实现过程简单、自动性高,生成的模型易于在国际互联网上进行分发、集成与共享。该方法的应用将有助于地质工作者向其他科技人员以及社会公众展示、分发自己拥有的钻孔信息,为以钻孔数据为代表的城市地质信息的社会化服务奠定基础。

近地空间环境要素三维建模与可视化仿真研究

提出了近地空间环境要素三维建模的静态模型和实测模型。根据近地空间环境各要素的特点,首先利用各种静态模式和实测数据构建三维空间数据场。然后对数据场进行六面体单元剖分,其中对实测得到的空间数据利用雅克比矩阵转换为规则六面体数据。最终,分别给出了中性大气、电离层等离子体、地球基本磁场和地球辐射带的几何模型,提出了一种适合于近地空间环境要素仿真的通用三维可视化方案。

基于智能手机和Google Earth构建钉螺资料数据库

目的利用智能手机和Google Earth的数字化、可视化功能,构建钉螺资料数据库。方法先给智能手机加载多点GPS软件。选择1块江滩查螺,先通过手机端采集调查框的GPS数据,将采集的原始数据以KML/KMZ格式导入计算机,将KML转化为Excel格式,录入实验室检查结果,实现原始螺情资料的数字化。再将Excel格式转化为KML/KMZ格式文件,导入Google Earth进行可视化展示。结果完成1块5 hm2江滩螺情数据采集,获得基于Google Earth的可视化螺情分布图,构建了钉螺资料数据库。通过钉螺资料数据库,可查询每个调查框的钉螺数、活螺数和感染螺数等数据。结论利用智能手机和Google Earth,实现了原始查螺数据的数字化管理。

地球数字产品的空间数学基础

在分析当前地球数字产品空间数学基础局限性的基础上 ,将地图投影概念由传统的曲面到平面的变换扩展为曲面到曲面的变换 ,提出一套适合于大型 GIS和地球数字产品的“地图投影”模型的实用模型 ,该模型的视图采用等距离切圆柱投影 ,度量空间是椭球面几何系统 ,符合计算机环境下 GIS视图与度量空间分离的特性。鉴于全球多分辨率连续可视化 ,精密可视化量算 ,三维、多维地球数据统一 ,标准的空间定位框架和只有在统一的空间系统内全球资源、生态环境数据才能进行精确的地理分析等四个方面的需要 ,从地图投影进到本模型将是方向和技术趋势。

Google Earth在传染病早期预警结果三维可视化中的应用

探讨GoogleEarth（GE）在传染病早期预警结果三维可视化中的应用。模拟实时监测系统，采用前瞻性时空扫描统计量对2005年上海市、江苏省、浙江省214个区县麻疹病例数据进行逐日前瞻性分析。选择其中部分预警结果，采用GE对其进行三维可视化呈现，完整展示预警结果中包含的时间、地域、实际发病数、理论发病数等若干相关重要信息。GE在传染病实时监测及早期预警中具有潜在的重要应用价值，可进一步研发将其与网络直报系统和聚集性探测方法集成的计算机系统。