Digital Earth: a new challenge and new vision

ABSTRACT

Digital Earth has seen great progress during the last 19 years. When it entered into the era of big data, Digital Earth developed into a new stage, namely one characterized by ‘Big Earth Data’, confronting new challenges and opportunities. In this paper we give an overview of the development of Digital Earth by summarizing research achievements and marking the milestones of Digital Earth’s development. Then, the opportunities and challenges that Big Earth Data faces are discussed. As a data-intensive scientific research approach, Big Earth Data provides a new vision and methodology to Earth sciences, and the paper identifies the advantages of Big Earth Data to scientific research, especially in knowledge discovery and global change research. We believe that Big Earth Data will advance and promote the development of Digital Earth.     

新一代数字地球平台与“数字中国”技术体系架构探讨

本文系统分析和总结了Google Earth的四大特点,及为地球科学研究、"数字地球"和"数字中国"的发展所带来的影响和启迪,提出了数字地球平台(DEP)的概念,并针对"数字中国"的建设,提出了建立"数字中国"的数据交换标准(DCML),提出了全新的以地学信息浏览器/空间信息服务器(G/S)结构为主的下一代数字地球、数字中国的技术体系架构,进一步对"数字中国"技术体系架构应遵循的原则进行了论述,对"数字中国"建设和应用服务进行了展望。     

数字地球及其军事应用初探

数字地球是全球信息化以及各国军事竞争的必然产物,在现代化战争和国防建设中具有十分重大意义。本文阐述了数字地球的概念及地位作用,研究了数字地球军事应用开发环境的构建,最后重点论述了数字地球在军事上的应用及应用现状。     

"数字佳木斯"总体框架研究

“数字佳木斯”建设是佳木斯市实施可持续发展的战略工程,是“数字中国”在佳木斯市的具体实现。作者通过大量的调查研究,结合现阶段“数字地球”技术的最新成果及发展方向,提出了“数字佳木斯”建设的总体框架,并提出了未来几年内“数字佳木斯”的建设构想。     

The role of GIS in Digital Earth education

Abstract

A growing number of educators worldwide have become convinced that geotechnologies – including geographic information systems (GIS), global positioning systems (GPS), and remote sensing – are key technologies to prepare students to be tomorrow's decision makers. Grappling with local, regional, and global issues of the 21^st century requires people who think spatially and who can use geotechnologies. Some educators teach geotechnologies as a discipline, emphasising skills. Other educators use geotechnologies as a tool to teach content, such as geography, history, environmental studies, Earth Science, biology, mathematics, economics and other disciplines. Issues such as traffic, population growth, urban sprawl, energy, water, crime, human health, biodiversity and sustainable agriculture are growing in complexity, exist at every scale and increasingly affect people's everyday lives. Each of these issues has a spatial component. Drivers for geotechnology education include educational content standards, constructivism, the school-to-career movement, active learning, citizenship education, authentic practice and assessment, interdisciplinary education, community connections and a sustained, increasing demand for GIS professionals. Digital Earth is an ideal framework for contextualising domains of inquiry. The Digital Earth community can have a significant impact on the growth of geotechnologies in education, and conversely, the growth of geotechnologies in education and society can foster the forward movement of Earth systems concepts.     

A novel confidence estimation method for neural networks in multispectral image classification

Abstract

The Digital Earth concept has attracted much attention recently and this approach uses a variety of earth observation data from the global to the local scale. Imaging techniques have made much progress technically and the methods used for automatic extraction of geo-ralated information are of importance in Digital Earth science. One of these methods, artificial neural networks (ANN) techniques, have been effectively used in classification of remotely sensed images. Generally image classification with ANN has been producing higher or equal mapping accuracies than parametric methods. Comparative studies have, in fact, shown that there is no discernible difference in classification accuracies between neural and conventional statistical approaches. Only well designed and trained neural networks can present a better performance than the standard statistical approaches. There are, as yet, no widely recognised standard methods to implement an optimum network. From this point of view it might be beneficial to quantify ANN's reliability in classification problems. To measure the reliability of the neural network might be a way of developing to determine suitable network structures. To date, the problem of confidence estimation of ANN has not been studied in remote sensing studies. A statistical method for quantifying the reliability of a neural network that can be used in image classification is investigated in this paper. For this purpose the method is to be based on a binomial experimentation concept to establish confidence intervals. This novel method can also be used for the selection of an appropriate network structure for the classification of multispectral imagery. Although the main focus of the research is to estimate confidence in ANN, the approach might also be applicable and relevant to Digital Earth technologies.     

The Sensor Web: systems of sensor systems

Abstract

Global Earth Observing System of Systems (GEOSS) presents a great challenge of System of Systems integration across organisational and political boundaries. One existing paradigm that can address the scale of the challenge is that of the Sensor Web. In this paradigm, the internet is evolving into an active, macro sensing instrument, capable of drawing sensory data from around the globe to the fingertips of individuals. The Sensor Web will support scientific research and facilitate transparent political decision making. This article presents some of the technologies explored and activities engaged in by the GEOSS Sensor Web community, towards achieving GEOSS goals.     

Review of the development of digital earth research during 1998–2015 based on a bibliometric analysis

ABSTRACT

Since Al Gore created the vision for Digital Earth in 1998, a wide range of research in this field has been published in journals. However, little attention has been paid to bibliometric analysis of the literature on Digital Earth. This study uses a bibliometric analysis methodology to study the publications related to Digital Earth in the Science Citation Index database and Social Science Citation Index database (via the Web of Science online services) during the period from 1998 to 2015. In this paper, we developed a novel keyword set for ‘Digital Earth’. Using this keyword set, 11,061 scientific articles from 23 subject categories were retrieved. Based on the searched articles, we analyzed the spatiotemporal characteristics of publication outputs, the subject categories and the major journals. Then, authors’ performance, affiliations, cooperation, and funding institutes were evaluated. Finally, keywords were examined. Through keyword clustering, research hotspots in the field of Digital Earth were detected. We assume that the results coincide well with the position of Digital Earth research in the context of big data.     

Evolution and implementation of the Digital Earth vision,technology and society

Abstract

Digital Earth's framework can be traced to evolutionary threads with historic foundations that fostered the fertile conceptual and technological incubation. These threads incorporate writings, such as those of the visionary engineering-genius, Buckminster Fuller, in conjunction with an array of space age developments in computers, internet and communications, satellites, and education. In 1998, when Vice President Al Gore articulated the Digital Earth Vision, he portrayed the vision based upon myriad technology factors for the intellectual foundation and sparked a worldwide phenomenon that fortuitously included the Chinese leadership's recognition and acceptance. The Beijing Declaration is recognised for its role promulgating the International Digital Earth Symposium series to promote better understanding of the impacts of Digital Earth technology and applications on behalf of all humankind. Combinations of industrial, academic, and government organisations have advanced the technological components necessary for implementing the Digital Earth Vision at a prodigious rate. Commercial leaders, such as Google, have accelerated the influence of large segments of society towards components of the Digital Earth Vision. However, challenges still remain regarding requisite collaboration on international standards for metadata, interoperability, and data formats for space and time that will affect Digital Earth implementation scenarios. Functional requirements for the model Digital Earth geobrowser remain to be fully articulated. The current paper presents an overview of the historical components, the key players on the international scene, the catalytic technological advances, and the societal response to the growth of the Digital Earth community.     

A digital earth platform for sustainability

ABSTRACT

Based on the experience of the International Society for Digital Earth (ISDE), this paper describes some challenges foreseen in order to develop a Digital Earth platform that can support the implementation of the Sustainable Development Goals. The use of ready-to-use derived geospatial information is essential. Future Earth’s methodology of ‘co-design’ aims to bring together natural, social scientists and decision makers to plan and carry out research for sustainability. Sustainability implies transdisciplinary research, but in order for scientists of different disciplines to work together, they will need to be able to share, access and use common data. This is by far not simple! While the good will to share data might exist, the associated technological, ethical and privacy issues are difficult to solve. An adequate e-infrastructure will be required. ISDE could consider to use the SDGs is the basis to develop the desired Digital Earth platform. This paper, by no means, covers everything for a Digital Earth platform, it aims to trigger research discussions and to have a good view about a starting point.     

Redefining the possibility of digital Earth and geosciences with spatial cloud computing

Abstract

Global challenges (such as economy and natural hazards) and technology advancements have triggered international leaders and organizations to rethink geosciences and Digital Earth in the new decade. The next generation visions pose grand challenges for infrastructure, especially computing infrastructure. The gradual establishment of cloud computing as a primary infrastructure provides new capabilities to meet the challenges. This paper reviews research conducted using cloud computing to address geoscience and Digital Earth needs within the context of an integrated Earth system. We also introduce the five papers selected through a rigorous review process as exemplar research in using cloud capabilities to address the challenges. The literature and research demonstrate that spatial cloud computing provides unprecedented new capabilities to enable Digital Earth and geosciences in the twenty-first century in several aspects: (1) virtually unlimited computing power for addressing big data storage, sharing, processing, and knowledge discovering challenges, (2) elastic, flexible, and easy-to-use computing infrastructure to facilitate the building of the next generation geospatial cyberinfrastructure, CyberGIS, CloudGIS, and Digital Earth, (3) seamless integration environment that enables mashing up observation, data, models, problems, and citizens, (4) research opportunities triggered by global challenges that may lead to breakthroughs in relevant fields including infrastructure building, GIScience, computer science, and geosciences, and (5) collaboration supported by cloud computing and across science domains, agencies, countries to collectively address global challenges from policy, management, system engineering, acquisition, and operation aspects.     

Geoinformatics and digital earth initiatives: a German perspective

Abstract

This paper discusses the role of Geoinformatics as a new scientific discipline designed for handling of geospatial information. Depending on the scientific background of the people involved in shaping the emerging discipline, emphasis may be placed on different aspects of Geoinformatics. Applications and developments may address geoscientific, spatial planning, or computer science related matters. The scientific field of Geoinformatics encompasses the acquisition and storing of geospatial data, the modelling and presentation of spatial information, geoscientific analyses and spatial planning, and the development of algorithms and geospatial database systems. It is the position of the author that these tools from Geoinformatics are necessary to bridge the gap between Digital Earth models and the real world with its real-world problems (‘connecting through location’). It is, however, crucial that Geoinformatics represents a coherent integrated approach to the acquisition, storage, analysis, modeling, presentation, and dissemination of geo-processes and not a patchwork solution of unconnected fields of activity. Geoinformatics is as such not a part of Geography, Surveying, or Computer Science, but a new self-contained scientific discipline. The current paper highlights international and national trends of the discipline and presents a number of Geoinformatics initiatives. The research and teaching activities of the newly formed Institute for Geoinformatics and Remote Sensing (IGF) at the University of Osnabrueck serve as an example for these initiatives. All these developments have lead to the long overdue formation of a scientific ‘Society for Geoinformatics’ (German: Gesellschaft für Geoinformatik – GfGI) in Germany.     

利用球体剖分瓦块构建真三维数字地球平台

全球离散网格是面向空间大数据的模型框架,常用于构建数字地球平台。基于球体的剖分瓦块不仅可以构建真三维的数字地球模型,而且可以实现天地一体化的空间数据集成、融合、表达和应用。本文详细论述了球体大圆弧QTM八叉树网格的剖分原理、网格几何特征分析和编解码方法等理论体系,并利用剖分瓦块实现了球体的任意分割以及地下、地表和空中实体的可视化建模。研究表明,球体QTM网格具有剖分规则简单、体系规整、几何特征明晰,适用性强等特点,尤其是可以推广到椭球。因而,该方案可用于天地一体化的空间数据的组织、管理与应用。     

Assessing global Sentinel-2 coverage dynamics and data availability for operational Earth observation (EO) applications using the EO-Compass

ABSTRACT

Sentinel-2 scenes are increasingly being used in operational Earth observation (EO) applications at regional, continental and global scales, in near-real time applications, and with multi-temporal approaches. On a broader scale, they are therefore one of the most important facilitators of the Digital Earth. However, the data quality and availability are not spatially and temporally homogeneous due to effects related to cloudiness, the position on the Earth or the acquisition plan. The spatio-temporal inhomogeneity of the underlying data may therefore affect any big remote sensing analysis and is important to consider. This study presents an assessment of the metadata for all accessible Sentinel-2 Level-1C scenes acquired in 2017, enabling the spatio-temporal coverage and availability to be quantified, including scene availability and cloudiness. Spatial exploratory analysis of the global, multi-temporal metadata also reveals that higher acquisition frequencies do not necessarily yield more cloud-free scenes and exposes metadata quality issues, e.g. systematically incorrect cloud cover estimation in high, non-vegetated altitudes. The continuously updated datasets and analysis results are accessible as a Web application called EO-Compass. It contributes to a better understanding and selection of Sentinel-2 scenes, and improves the planning and interpretation of remote sensing analyses.     

A European perspective on Digital Earth

Abstract

The purpose of this paper is to contribute to the definition of a European perspective on Digital Earth (DE), identify some actions that can contribute to raise the awareness of DE in the European context and thus strengthen the European contribution to the International Society for Digital Earth (ISDE). The paper identifies opportunities and synergies with the current policy priorities in Europe (Europe 2020, Innovation Union and Digital Agenda) and highlights a number of key areas to advance the development of DE from a European perspective: (1) integrating scientific research into DE; (2) exploiting the Observation Web with human-centred sensing; and (3) governance, including the establishment of stronger linkages across the European landscape of funding streams and initiatives. The paper is offered also as a contribution to the development of this new vision of DE to be presented at the next International DE Conference in Perth, Australia, in August 2011. The global recognition of this new vision will then reinforce the European component and build a positive feedback loop for the further implementation of DE across the globe.     

“全球生态环境遥感监测年度报告”回顾：2012—2021

持续开展生态环境遥感监测对于认识和评估全球生态系统可持续性和人类生存环境状况具有重要的科学意义,是面向“推进生态文明建设”和“构建地球生命共同体”等目标和愿景,提升综合地球观测能力和应对全球生态环境挑战的务实行动。为此,中华人民共和国科学技术部国家遥感中心聚焦可持续发展、气候变化、防灾减灾和韧性城市等优先事项,通过政府部门、科研机构、国际组织和社会公众的协同,连续十年（2012年—2021年）发布和共享了“全球生态环境遥感监测年度报告”共29个专题报告和100余个遥感数据集。此项工作取得的成果包括：在遥感技术方法创新方面,基于国产高分辨率卫星和多源遥感影像,针对生态系统状况和人类活动痕迹的高精度遥感监测取得了一批具有自主知识产权的算法模型和数据产品;在人类生存环境认知方面,显著提升了公众对粮食安全、气候变化、城市扩展、土地退化和自然灾害风险等全球生态环境热点问题的科学认知;在生态环境重点区域方面,对“一带一路”、南极、非洲、东盟等典型区域开展精细化监测和评估。该项工作是中国作为地球观测组织GEO（Group on Earth Observations）联合主席国对国际社会的实质贡献,为相关机构和部门决策制定提供了重要的信息参考。本论文在此项工作开展十周年之际,系统阐述和总结了全球生态环境遥感监测年度报告的主要内容和亮点成果,并对未来发展提出展望。     

Production of global land cover data – GLCNMO

Abstract

Global land cover is one of the fundamental contents of Digital Earth. The Global Mapping project coordinated by the International Steering Committee for Global Mapping has produced a 1-km global land cover dataset – Global Land Cover by National Mapping Organizations. It has 20 land cover classes defined using the Land Cover Classification System. Of them, 14 classes were derived using supervised classification. The remaining six were classified independently: urban, tree open, mangrove, wetland, snow/ice, and water. Primary source data of this land cover mapping were eight periods of 16-day composite 7-band 1-km MODIS data of 2003. Training data for supervised classification were collected using Landsat images, MODIS NDVI seasonal change patterns, Google Earth, Virtual Earth, existing regional maps, and expert's comments. The overall accuracy is 76.5% and the overall accuracy with the weight of the mapped area coverage is 81.2%. The data are available from the Global Mapping project website (http://www.iscgm.org/). The MODIS data used, land cover training data, and a list of existing regional maps are also available from the CEReS website. This mapping attempt demonstrates that training/validation data accumulation from different mapping projects must be promoted to support future global land cover mapping.     

地球格网化剖分及其度量问题

地球剖分网格(或全球位置定位框架)系一种科学简明的空间参考系统,是地球信息数据的离散化、准确化、系统化的表现,这是地理信息科学和数字地球中重要的基础性问题,是全部地理计算的源头和归宿。近年来,随着GPS、北斗等卫星系统日趋发展和全球化应用,此相关于全球三维位置准确性、度量和全部空间分析准确性等基础问题受到人们高度重视。本文首先针对多年来地球剖分网格研究的进展和不足,提出和分析了网格数据的质量的若干问题,即剖分的完整性、逻辑一致性、准确度和一些相关问题;然后面向剖分中的定位和度量,指出了剖分对象及其度量空间特征,剖析了"3维结构及厘米级准确度"的革命性需求将对GIS体系和剖分科技体系发展产生重大的影响;接着,着重指出地球剖分的椭球三维途径的主体和剖分途径,论述了加强剖分基础理论阐述的内容和意义,并介绍了地图代数在地球剖分基础对象、椭球三维剖分和理论途径和相应试验。最后,课题组认为椭球型、(B,L,H)三组正交曲面剖分是地球剖分工作的正确途径,建议大力强化剖分理论基础研究,发展和完善剖分的标准体系,迅速创建地球剖分试验平台。     

智慧地球时代测绘地理信息学的新使命

本文首先指出智慧地球是数字地球、物联网和云计算等有机的融合,随后分析了智慧地球的主要特性,并重点阐述了智慧地球时代测绘地理信息学的新使命。作者认为我们已经从绘制地形图为主的小测绘发展成为当今以地理空间信息服务为主的大测绘,现在必须抓住机遇,不失时机地拓展智慧地球时代测绘地理信息学的新使命,将传统测绘提升为能够实时、智能地采集和处理海量空间数据、提供空间信息和知识服务的智慧测绘新阶段。