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1.
《International Journal of Digital Earth》2013,6(3):259-278
Abstract This paper introduces a new concept, distributed geospatial information processing (DGIP), which refers to the process of geospatial information residing on computers geographically dispersed and connected through computer networks, and the contribution of DGIP to Digital Earth (DE). The DGIP plays a critical role in integrating the widely distributed geospatial resources to support the DE envisioned to utilise a wide variety of information. This paper addresses this role from three different aspects: 1) sharing Earth data, information, and services through geospatial interoperability supported by standardisation of contents and interfaces; 2) sharing computing and software resources through a GeoCyberinfrastructure supported by DGIP middleware; and 3) sharing knowledge within and across domains through ontology and semantic searches. Observing the long-term process for the research and development of an operational DE, we discuss and expect some practical contributions of the DGIP to the DE. 相似文献
2.
《International Journal of Digital Earth》2013,6(2):240-245
Abstract Digital Earth is an important field of information technology and a research frontier of geosciences in the 21st century. So far, the Grid computing technique is one of the best solutions for Digital Earth infrastructure. Digital Earth can only be realised through the interaction of people, heterogeneous computing resources, information systems, and instruments, all of which are geographically and organisationally dispersed. Earth observation (EO) includes information acquisition, processing and applications. Information acquisition provides a vast amount of spatial data for building the fabric resource infrastructure. Information processing means that spatial information processing middleware is used with large amounts of secure Grid computing resources for real-time processing of all kinds of spatial data. We are currently working on the development of core-middleware for EO data processing and applications for the Digital Earth Prototype System, which is available in the Institute of Remote Sensing Applications (IRSA), Chinese Academy of Sciences (CAS) The further results will be available soon. 相似文献
3.
《International Journal of Digital Earth》2013,6(5):345-363
Driven by the rise of Web 2.0 and the non-stop spread of mobile device sensors, the concept of Public Participation GIS (PPGIS) is knowing a revolutionary era which perfectly fits the new vision of Digital Earth (DE). This research investigates the opportunity to build up a PPGIS prototype with completely Free and Open Source Software (FOSS) architecture, in which data directly come from field surveys carried out by users. A sample application related to urban monitoring is addressed, which concentrates on user field-collected data concerning reports of road pavement damages. Open Data Kit suite allows users to collect geotagged multimedia information using mobile devices with onboard location sensors (e.g. a Global Positioning System receiver). On field-captured data are sent to a server and stored into a PostgreSQL database with PostGIS spatial extension. GeoServer then disseminates data on the Web. On the client-side, different solutions allow data visualization on both desktop computers and mobile devices. The designed architecture provided support for FOSS usage in the process of gathering, uploading, and Web publishing information collected in situ. The implementation of the developed PPGIS could thus substantially increase public active participation in data creation and sharing, besides enlarging DE knowledge up to the local level. 相似文献
4.
《International Journal of Digital Earth》2013,6(4):271-284
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. 相似文献
5.
6.
ABSTRACTThe Moon, Earth’s only natural satellite, is a potential new platform for Earth observation. Moreover, with the wide applicability of the angular information from remote sensing data, it has been attracting increasingly more attention. Accordingly, this study focuses on the angular characteristics of Moon-based Earth observations. Using ephemeris DE430 and Earth orientation parameters, the position and attitude of the Sun, Earth, and Moon were obtained and their coordinates normalized to a single framework using coordinate transformations between the related reference systems. Then, an angular geometric model of Moon-based Earth observations was constructed, and the corresponding angular algorithms were presented. The results revealed the angular range and distribution characteristics of Moon-based Earth observations. For every point on the surface of the Earth, the view and solar zenith angles all vary widely, which decreases with increasing latitude. The view and solar zenith angles all vary widely with the largest range of values in the equatorial and polar regions and a smaller range of values in mid-latitudes. Furthermore, the range of solar angles of Moon-based Earth observations is the same as that of all-time solar angles, indicating the potential for monitoring and understanding large-scale geoscientific phenomena using Moon-based Earth observations. 相似文献
7.
数字地球建设中的地理空间Metadata研究 总被引：2，自引：0，他引：2
为解决数字地球建设中现有海量地理空间信息的共建共享,有效管理和利用,结合国际地理空间Metadata标准规范,对数字地球建设中所需的地理空间Metadata的定义,作用,分类,内容,实现模型与实例及其应用进行详细研究和设计,提出用于数字地球建设的地理空间Metadata网络管理系统解决方案,并设计实现了原型系统,为数字地球建设中现有海量地理空间信息的有效管理和共建共享提供了理论基础和切实可行的技术支撑。对国家空间信息基础设施建设和数字地球建设具有重要的推动作用和深远的社会意义。 相似文献
8.
《International Journal of Digital Earth》2013,6(1):38-52
A Parasitic Model is proposed in this study for Digital Earth running on mobile phones through a mobile network. Because of mobile phones' limited capabilities in high-performance computing, rendering, storing, and networking (CRSN), these functions are accomplished by a superior host computer in this model. Rendered virtual scenes are compressed in a time-series as a data stream and are sent to the mobile phone through a mobile network, thus allowing Digital Earth to be operated on a mobile phone. This study examines a prototype and shows that a Mobile Digital Earth based on a Parasitic Model can achieve functionality beyond the mobile phone's actual hardware capabilities and can reduce network traffic. These results demonstrate quasi-real-time interactions, but with bandwidth increases in next-generation mobile networks such as 4G and 5G, there is potential for real-time interactions in the near future. 相似文献
9.
《International Journal of Digital Earth》2013,6(5):398-416
Abstract The vision of Digital Earth (DE) put recently forward under the auspices of the International Society for DE extends the paradigm of spatial data infrastructures by advocating an interactive and dynamic framework based on near-to-real time information from sensors and citizens. This paper contributes to developing that vision and reports the results of a two-year research project exploring the extent to which it is possible to extract information useful for policy and science from the large volumes of messages and photos being posted daily through social networks. Given the noted concerns about the quality of such data in relation to that provided by authoritative sources, the research has developed a semi-automatic workflow to assess the fitness for purpose of data extracted from Twitter and Flickr, and compared them to that coming from official sources, using forest fires as a case study. The findings indicate that we were able to detect accurately six of eight major fires in France in the summer of 2011, with another four detected by the social networks but not reported by our official source, the European Forest Fire Information Service. These findings and the lessons learned in handling the very large volumes of unstructured data in multiple languages discussed in this study provide useful insights into the value of social network data for policy and science, and contribute to advancing the vision of DE. 相似文献
10.
苗前军 《测绘与空间地理信息》1999,(3)
本文通过对数字地球的诠释,结合与地相学的本质联系,论述了二者的形成与发展的关联程度,提出了数字地球是地相学的“量化”;地相学是数字地球的理论支撑与生存、发展的土壤,也是数字地球的学科定位“解”。进而,阐明数字时空的实现是数字地球更宽泛的归宿。 相似文献
11.
《International Journal of Digital Earth》2013,6(1):148-154
Abstract Three-dimensional (3D) visualisations are an interesting method for representing model outcomes. Most visualisation techniques require expensive software and a lot of time to create them. When the visualisations need to be adapted frequently, a faster and more flexible method is needed. The first step of the proposed model is to create the 3D elements. These elements are combined with the base map, and distributed to the public using Google Earth. Both freely available and commercial software are used in this process. 相似文献
12.
Global geospatial data from Earth observation: status and issues 总被引：1，自引：0，他引：1
ABSTRACTData covering the whole of the surface of the Earth in a homogeneous and reliable manner has been accumulating over many years. This type of data became available from meteorological satellites from the 1960s and from Earth-observing satellites at a small scale from the early 1970s but has gradually accumulated at larger scales up to the present day when we now have data covering many environmental themes at large scales. These data have been used to generate information which is presented in the form of global data sets. This paper will give a brief introduction to the development of Earth observation and to the organisations and sensors which collect data and produce global geospatial data sets. Means of accessing global data sets will set out the types of data available that will be covered. Digital elevation models are discussed in a separate section because of their importance in georeferencing image data as well as their application to analysis of thematic data. The paper will also examine issues of availability, accuracy, validation and reliability and will look at future challenges. 相似文献
13.
《International Journal of Digital Earth》2013,6(1):1-3
ABSTRACTDigital 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. 相似文献
14.
The present study aims to extend the traditional rotation theory of the rotational-symmetric Earth to the triaxial Earth.We re-formulate the Liouville equations and their general solutions for the triaxial nonrigid Earth and find that the traditional theory intro-duces some theoretical errors in modeling the excitation functions.Furthermore,we apply that theory to the atmospheric excitation and find that theoretical errors should not be neglected given the present measurement accuracy.Thus we conclude that the traditional the-ory of the rotation of the rotational-symmetric Earth should be revised and upgraded to include the effects of the Earth’s triaxiality. 相似文献
15.
《International Journal of Digital Earth》2013,6(1):3-16
The Digital Earth (DE) movement is gaining momentum. Much of it is unstructured. This paper examines a number of recent developments including those in health sensors (Wearable Absence, Q-Sensor, and Guardian Angels) and systems frameworks (Gelernter's Mirror Worlds, Virtual Australia, and New Zealand). Consideration is given to the implications of DE for citizens and on citizen science, including those of ethics. A suite of principles to guide the development of DE is proposed. 相似文献
16.
《International Journal of Digital Earth》2013,6(1):28-50
Abstract With the proposition of the Digital Earth (DE) concept, Virtual Geographic Information System (VGIS) has started to play the role of a Digital Earth prototype system. Many core problems involved in VGIS, such as out-of-core management and interactive rendering of very large scale terrain and image data, have been well studied in the past decades. However, the jitter problem, a common problem in VGIS that often causes annoying visual artefacts and deteriorates the output image quality, draws little attention. In this paper, after an intensive analysis of the jitter problem, a comprehensive framework is proposed to address such a problem while accounting for the characteristics of different data types in VGIS, such as terrain or ocean mesh data, vector data and 3-D model data. Specifically, this framework provides an improved dynamic local coordinate system (DLCS) method for terrain or ocean mesh data. For vector data, the framework provides a simple and effective multiple local coordinate systems (MLCS) method. The framework provides a MLCS method for 3-D model data making full use of the existing local coordinate system of the model. The advantages of the proposed methods over current approaches are analysed and highlighted through case studies involving large GIS datasets. 相似文献
17.
H. Fan 《Journal of Geodesy》1998,72(9):511-515
Historically, the mean Earth ellipsoid is obtained by fitting an ellipsoid of revolution to the geoid. Such an ellipsoid,
however, does not necessarily best fit the physical surface of the Earth due to the existence of topography outside the geoid.
In this paper, we present a purely geometrically defined Earth ellipsoid that best fits the physical surface of the Earth
so that the resulting ellipsoidal height attains minimum global mean square value. Using a global digital terrain model and
a global geopotential model, the size, shape and position of such an Earth ellipsoid have been numerically estimated.
Received: 6 September 1996 / Accepted: 1 April 1998 相似文献
18.
Analytical versus semi-analytical determinations of the Oppolzer terms for a non-rigid Earth 总被引：1，自引：1，他引：0
Estimations of the Oppolzer terms for the angular momentum and rotation axes of a non-rigid Earth are obtained from two different
approaches and compared. The first approach is an analytical method which relies on the solutions of the Liouville equations
for a two-layer Earth model. The Oppolzer terms are evaluated from analytical expressions. The results are then compared to
those calculated from Wahr's theory of nutation for a non-rigid Earth, which is the second approach used. Results are obtained
for the main nutation frequencies and for the precession case. The differences between the two solutions are generally quite
small (the relative error is most of the time under 8%) and are, for a large part, due to successive approximations and truncation
effects during their determination. Departures of the results from the two methods are significantly larger for frequencies
near the Free Core Nutation (FCN) resonance. This is particularly true for the Oppolzer terms of the angular momentum axis.
The Earth model adopted is a little bit different in each case: for the Liouville system solution, we have limited the model
to a homogeneous elastic mantle and a homogeneous liquid core. Another source of some of the small differences in the results
is the presence of a solid inner core in Wahr's theory. We confirm through the analytical calculation the strong effect of
the core on the Oppolzer terms of the angular momentum axis for a non-rigid Earth at the precession frequency. Finally, an
application is given in the determination of the axes' position at J2000 for a non-rigid Earth.
Received: 23 February 1998 /Accepted: 18 November 1998 相似文献
19.
《International Journal of Digital Earth》2013,6(4):297-312
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. 相似文献
20.
《International Journal of Digital Earth》2013,6(10):1055-1069
ABSTRACTWhile impressive direct geolocation accuracies better than 5.0?m CE90 (90% of circular error) can be achieved from the last DigitalGlobe’s Very High Resolution (VHR) satellites (i.e. GeoEye-1 and WorldView-1/2/3/4), it is insufficient for many precise geodetic applications. For these sensors, the best horizontal geopositioning accuracies (around 0.55?m CE90) can be attained by using third-order 3D rational functions with vendor’s rational polynomial coefficients data refined by a zero-order polynomial adjustment obtained from a small number of very accurate ground control points (GCPs). However, these high-quality GCPs are not always available. In this work, two different approaches for improving the initial direct geolocation accuracy of VHR satellite imagery are proposed. Both of them are based on the extraction of three-dimensional GCPs from freely available ancillary data at global coverage such as multi-temporal information of Google Earth and the Shuttle Radar Topography Mission 30?m digital elevation model. The application of these approaches on WorldView-2 and GeoEye-1 stereo pairs over two different study sites proved to improve the horizontal direct geolocation accuracy values around of 75%. 相似文献