Digital earth:yesterday,today,and tomorrow

The concept of Digital Earth(DE)was formalized by Al Gore in 1998.At that time the technologies needed for its implementation were in an embryonic stage and the concept was quite visionary.Since then digital technologies have progressed significantly and their speed and pervasiveness have generated and are still causing the digital transformation of our society.This creates new opportunities and challenges for the realization of DE.‘What is DE today?’,‘What could DE be in the future?’,and‘What is needed to make DE a reality?’.To answer these questions it is necessary to examine DE considering all the technological,scientific,social,and economic aspects,but also bearing in mind the principles that inspired its formulation.By understanding the lessons learned from the past,it becomes possible to identify the remaining scientific and technological challenges,and the actions needed to achieve the ultimate goal of a‘Digital Earth for all’.This article reviews the evolution of the DE vision and its multiple definitions,illustrates what has been achieved so far,explains the impact of digital transformation,illustrates the new vision,and concludes with possible future scenarios and recommended actions to facilitate full DE implementation.

Virtual earth cloud: a multi-cloud framework for enabling geosciences digital ecosystems

Humankind is facing unprecedented global environmental and social challenges in terms of food,water and energy security,resilience to natural hazards,etc.To address these challenges,international organizations have defined a list of policy actions to be achieved in a relatively short and medium-term timespan.The development and use of knowledge platforms is key in helping the decision-making process to take significant decisions(providing the best available knowledge)and avoid potentially negative impacts on society and the environment.Such knowledge platforms must build on the recent and next coming digital technologies that have transformed society–including the science and engineering sectors.Big Earth Data(BED)science aims to provide the methodologies and instruments to generate knowledge from numerous,complex,and diverse data sources.BED science requires the development of Geoscience Digital Ecosystems(GEDs),which bank on the combined use of fundamental technology units(i.e.big data,learning-driven artificial intelligence,and network-based computing platform)to enable the development of more detailed knowledge to observe and test planet Earth as a whole.This manuscript contributes to the BED science research domain,by presenting the Virtual Earth Cloud:a multi-cloud framework to support GDE implementation and generate knowledge on environmental and social sustainability.

Publishing Eurac Research data on the GEOSS Platform

This paper is the third of a series that introduces some of the main dataset resources presently shared through the GEOSS Platform. The GEOSS Platform is a brokering infrastructure that brokers more than 190 autonomous information systems and data catalogs;it was created to provide the technological tool to implement the Global Earth Observation System of Systems (GEOSS). This manuscript focuses on the analysis of Eurac Research datasets and illustrates the data publishing process to enroll the Eurac Research Data Provider to the GEOSS Platform through the administrative and technical registrations. The study provides an analysis of the GEOSS user searches for Eurac Research data in order to understand the main use of datasets of an important Data Provider.

GEOSS Platform data content and use

The GEOSS Platform is a key contribution to the goal of building the Global Earth Observation System of Systems(GEOSS).It enables a harmonized discovery and access of Earth observation data,shared online by heterogeneous organizations worldwide.This work analyzes both what is made available in the GEOSS Platform by the data providers and how users are utilizing it including multiyear trends,updating a previous analysis published in 2017.The present statistics derive from a 2021 EOValue report funded by the European Commission.The offer of GEOSS Platform data has been the object of various analyses,including data provider characterization,data sharing trends,and data characterization(comprising metadata quality analysis,thematic analysis,responsible party identification,spatial–temporal coverage).GEOSS data demand has also been the object of several analyses,including data consumer characterization,utilization trends,and requested data characterization(comprising thematic analysis,spatial–temporal coverage,and popularity).Among thefindings,a large amount of shared data,mostly from satellite sources,emerges with an issue of low metadata quality and related discovery match.Moreover,the trend in usage is decreasing.Therefore,the progressive disconnection of the GEOSS platform from its data Providers and Users and other possible causes are also reported.

Publishing NextGEOSS data on the GEOSS Platform

This paper is the second of a series that describes some of the main dataset resources presently shared through the GEOSS Platform. The GEOSS Platform was created as the technological tool to implement interoperability among the Global Earth Observation System of Systems (GEOSS);it is a brokering infrastructure that presently brokers more than 190 autonomous data catalogs and information systems. This paper is focused on the analysis of the NextGEOSS datasets describing the data publishing process from NextGEOSS to the GEOSS platform. In particular, both the administrative registration and the technical registration were taken into consideration. One of the most important data shared by the GEOSS Platform are the NextGEOSS datasets: the present study provides some insights in terms of GEOSS user searches for NextGEOSS data.

Publishing China satellite data on the GEOSS Platform

This paper is the first of a series that describes some of the main dataset resources presently shared through the GEOSS Platform.The GEOSS Platform has been created to provide the technological tool to implement the Global Earth Observation System of Systems(GEOSS);it is a brokering infrastructure that presently brokers more than 190 autonomous data catalogs and information systems.The paper analyses the China Satellite datasets and describes the data publishing process from China GEOSS Data Provider to the GEOSS Platform considering both administrative registration as well as the technical registration.The China Satellite datasets are considered as one of the most important satellite data shared by the GEOSS Platform.The analysis provides some insights as well about GEOSS user searches for China Satellite datasets.

Big Earth Data science:an information framework for a sustainable planet

The digital transformation of our society coupled with the increasing exploitation of natural resources makes sustainability challenges more complex and dynamic than ever before.These changes will unlikely stop or even decelerate in the near future.There is an urgent need for a new scientific approach and an advanced form of evidence-based decisionmaking towards the benefit of society,the economy,and the environment.To understand the impacts and interrelationships between humans as a society and natural Earth system processes,we propose a new engineering discipline,Big Earth Data science.This science is called to provide the methodologies and tools to generate knowledge from diverse,numerous,and complex data sources necessary to ensure a sustainable human society essential for the preservation of planet Earth.Big Earth Data science aims at utilizing data from Earth observation and social sensing and develop theories for understanding the mechanisms of how such a social-physical system operates and evolves.The manuscript introduces the universe of discourse characterizing this new science,its foundational paradigms and methodologies,and a possible technological framework to be implemented by applying an ecosystem approach.CASEarth and GEOSS are presented as examples of international implementation attempts.Conclusions discuss important challenges and collaboration opportunities.

Towards a knowledge base to support global change policy goals

In 2015,it was adopted the 2030 Agenda for Sustainable Development to end poverty,protect the planet and ensure that all people enjoy peace and prosperity.The year after,17 Sustainable Development Goals(SDGs)officially came into force.In 2015,GEO(Group on Earth Observation)declared to support the implementation of SDGs.The GEO Global Earth Observation System of Systems(GEOSS)required a change of paradigm,moving from a data-centric approach to a more knowledge-driven one.To this end,the GEO System-of-Systems(SoS)framework may refer to the well-known Data-Information-Knowledge-Wisdom(DIKW)paradigm.In the context of an Earth Observation(EO)SoS,a set of main elements are recognized as connecting links for generating knowledge from EO and non-EO data–e.g.social and economic datasets.These elements are:Essential Variables(EVs),Indicators and Indexes,Goals and Targets.Their generation and use requires the development of a SoS KB whose management process has evolved the GEOSS Software Ecosystem into a GEOSS Social Ecosystem.This includes:collect,formalize,publish,access,use,and update knowledge.ConnectinGEO project analysed the knowledge necessary to recognize,formalize,access,and use EVs.The analysis recognized GEOSS gaps providing recommendations on supporting global decision-making within and across different domains.

A view-based model of data-cube to support big earth data systems interoperability

Big Earth Data-Cube infrastructures are becoming more and more popular to provide Analysis Ready Data,especially for managing satellite time series.These infrastructures build on the concept of multidimensional data model(data hypercube)and are complex systems engaging different disciplines and expertise.For this reason,their interoperability capacity has become a challenge in the Global Change and Earth System science domains.To address this challenge,there is a pressing need in the community to reach a widely agreed definition of Data-Cube infrastructures and their key features.In this respect,a discussion has started recently about the definition of the possible facets characterizing a Data-Cube in the Earth Observation domain.This manuscript contributes to such debate by introducing a view-based model of Earth Data-Cube systems to design its infrastructural architecture and content schemas,with the final goal of enabling and facilitating interoperability.It introduces six modeling views,each of them is described according to:its main concerns,principal stakeholders,and possible patterns to be used.The manuscript considers the Business Intelligence experience with Data Warehouse and multidimensional“cubes”along with the more recent and analogous development in the Earth Observation domain,and puts forward a set of interoperability recommendations based on the modeling views.

Exploring the depths of the global earth observation system of systems

This paper explores for the first time the contents,structure and relationships across institutions and disciplines of a global Big Earth Data cyber-infrastructure:the Global Earth Observation System of System(GEOSS).The analysis builds on 1.8 million metadata records harvested in GEOSS.Because this set includes almost all the major large data collections in GEOSS,the analysis represents more than 80%of all the data made available through this global system.We explore two major aspects:the collaborative networks and the thematic coverage in GEOSS.The first connects the contributing organisations through the more than 200,000 keywords used in the systems,and then explores who is citing whom,a proxy for of institutional thickness.The thematic coverage is analysed through neural network algorithms,first on the keywords,and then on the corpus of 653 million lemmatised lower case words built from the titles and abstracts of all 1.8 million metadata records.The findings not only give a good overview of the GEOSS data universe,but offer immediate priorities on how to increase the usability of GEOSS through improved data management,and the opportunity to augment the metadata with high level concept that synthetise well the contents of the data-set.

Big Data Analytics for Earth Sciences:the EarthServer approach

Big Data Analytics is an emerging field since massive storage and computing capabilities have been made available by advanced e-infrastructures.Earth and Environmental sciences are likely to benefit from Big Data Analytics techniques supporting the processing of the large number of Earth Observation datasets currently acquired and generated through observations and simulations.However,Earth Science data and applications present specificities in terms of relevance of the geospatial information,wide heterogeneity of data models and formats,and complexity of processing.Therefore,Big Earth Data Analytics requires specifically tailored techniques and tools.The EarthServer Big Earth Data Analytics engine offers a solution for coverage-type datasets,built around a high performance array database technology,and the adoption and enhancement of standards for service interaction(OGC WCS and WCPS).The EarthServer solution,led by the collection of requirements from scientific communities and international initiatives,provides a holistic approach that ranges from query languages and scalability up to mobile access and visualization.The result is demonstrated and validated through the development of lighthouse applications in the Marine,Geology,Atmospheric,Planetary and Cryospheric science domains.

Towards integrated essential variables for sustainability

Measuring the achievement of a sustainable development requires the integration of various data sets and disciplines describing bio-physical and socio-economic conditions.These data allow characterizing any location on Earth,assessing the status of the environment at various scales(e.g.national,regional,global),understanding interactions between different systems(e.g.atmosphere,hydrosphere,biosphere,geosphere),and modeling future changes.The Group on Earth Observations(GEO)was established in 2005 in response to the need for coordinated,comprehensive,and sustained observations related to the state of the Earth.GEO’s global engagement priorities include supporting the UN 2030 Agenda for Sustainable Development,the Paris Agreement on Climate,and the Sendai Framework for Disaster Risk Reduction.A proposition is made for generalizing and integrating the concept of EVs across the Societal Benefit Areas of GEO and across the border between SocioEconomic and Earth systems EVs.The contributions of the European Union projects ConnectinGEO and GEOEssential in the evaluation of existing EV classes are introduced.Finally,the main aim of the 10 papers of the special issue is shortly presented and mapped according to the proposed typology of SBA-related EV classes.

GEOEssential–mainstreaming workflows from data sources to environment policy indicators with essential variables

When defining indicators on the environment,the use of existing initiatives should be a priority rather than redefining indicators each time.From an Information,Communication and Technology perspective,data interoperability and standardization are critical to improve data access and exchange as promoted by the Group on Earth Observations.GEOEssential is following an end-user driven approach by defining Essential Variables(EVs),as an intermediate value between environmental policy indicators and their appropriate data sources.From international to local scales,environmental policies and indicators are increasingly percolating down from the global to the local agendas.The scientific business processes for the generation of EVs and related indicators can be formalized in workflows specifying the necessary logical steps.To this aim,GEOEssential is developing a Virtual Laboratory the main objective of which is to instantiate conceptual workflows,which are stored in a dedicated knowledge base,generating executable workflows.To interpret and present the relevant outputs/results carried out by the different thematic workflows considered in GEOEssential(i.e.biodiversity,ecosystems,extractives,night light,and food-water-energy nexus),a Dashboard is built as a visual front-end.This is a valuable instrument to track progresses towards environmental policies.

Multi-scale hydrological system-of-systems realized through WHOS:the brokering framework

Global Change challenges are now systematically recognized and tackled in a growingly coordinated manner by intergovernmental organizations such as the United Nations.Heterogeneous observing networks provide the founded data sources to assess the Earth environmental status and take sound decisions to achieve a sustainable development.WMO Hydrological Observing System(WHOS)allows to discover and access historical and near real time hydrological observations.WHOS represents the hydrological contribution to the wider WIGOS-WIS system of WMO.It is a digital ecosystems framework contributed by a set of data providers and technical support centers.In this framework,three regional pilots were successfully completed.The WHOS architecture applies the services brokering style,implemented through the Discovery and Access Broker technology.A brokering approach makes a global system of systems possible and sustainable,where the different enterprise systems are enabled to interoperate,despite they implement heterogeneous communication interfaces and data models.In this manuscript,the WHOS brokering solution is detailed by recurring to the definition of a set of transversal viewpoints to describe the important aspects of the complex ecosystem–namely:enterprise,information,computational,engineering,and technological views.Finally,the three regional pilot ecosystems are described as successful cases of WHOS implementation.

The implementation of international geospatial standards for earth and space sciences

The Earth and Space Sciences Informatics division of European Geosciences Union(EGU)and the Open Geospatial Consortium jointly organised a special event entitled:‘Implementation of international geospatial standards for earth and space sciences event’
at the EGU General Assembly meeting held in Vienna,April 2009.The event objectives included:(a)to discuss the integration of information systems from different geosciences disciplines;(b)to promote and discuss the present process to scale from specific and monolithic systems towards independent and modular enabling infrastructures
forming an earth system science(ESS)infrastructure;and(c)to show some of the latest advances in implementing open standards.This manuscript introduces the event motivations and describes the abstract and holistic framework,which can be used to situate the topics and the developments presented by the event speakers.This manuscript introduces important,and relatively new technologies to build a multi-disciplinary geosciences information system:the System of Systems approach and the Model Driven Approach.To achieve that,three important information infrastructure categories are recognised:(a)ESS information infrastructure;(b)geospatial information infrastructure;and(c)distributed information infrastructure.Digital Earth should support the discussed framework to accelerate information transfer from theoretical discussions to applications,in all fields related to global climate change,natural disaster prevention and response,new energy-source development,agricultural and food security,and urban planning and management.

Towards Earth and Space Science digital infrastructures: network, computing and data services

Earth and Space scientists are engaged in integrating knowledge stemming from different disciplines about the constituent parts of the complex Sun-Earth system with the objective of understanding its properties as a whole.Earth and Space system analysis is as real a challenge for information technology as it is for scientists.In fact,the scope and complexity of Earth and Space system investigations demand the formation of distributed,multidisciplinary collaborative teams.The development and deployment of advanced digital infrastructures(e.g.e-infrastructure and cyberinfrastructures)will support the needs of the Earth and Space Systems Science Community and facilitate multidisciplinary knowledge integration.

EDITORIAL

The Earth and space sciences are rapidly implementing international open standards for discovery,access,and processing of geospatial information.These standards provide for interoperability well tuned to the Earth and space sciences,because the standards were developed by members of the same community and are now being refined as best practices.