ConnectinGEO: Identifying and Prioritizing Gaps in Earth Observations


Communication across in-situ Earth observation networks and data sharing is essential to meeting sustainable development goals.

As we seek to better understand the Earth’s climate, natural resources, and ecosystems, the information provided by interconnected Earth observation networks is essential to decision-making.

The Global Earth Observation System of Systems (GEOSS) connects policymakers with Earth observations data. The Group on Earth Observations (GEO) has identified eight Societal Benefit Areas (SBAs) which support the application of Earth observing information to society’s needs. In many cases, they also support the United Nation’s Sustainable Development Goals (SDGs), particularly those needing Earth observations data.

However, gaps exist in the Earth observations data, which can make addressing SBAs and SDGs difficult. One of the missions of ConnectinGEO, which stands for Coordinating an Observation Network of Networks EnCompassing satellite and IN-situ, was to identify the gaps in European observations, as well as gaps in processing, access, usability and capacity. ConnectinGEO was completed in January 2017.

For two years, ConnectinGEO sought to address a number of major goals:

    • Establish a European Network of Earth Observation Networks (ENEON)
    • Formulate essential variables (EVs) using a goal-based approach for prioritizing and monitoring observations
    • Implement an observation inventory
    • Populate the socio-economic and environmental information needs (SEE IN) knowledge base
    • Carry out a gap analysis
  • Strengthen the dialogue between the industrial and research sectors in the domain of Earth observations.

As the two-year project with more than 10 partners has come to a close, Dr. Joan Masó, a researcher at the Ecological and Forestry Applications Research Centre (CREAF), and Ian McCallum, a researcher at Earth Observation Systems Group of the Ecosystems Services and Management Program at International Institute for Applied Systems and Analysis, are reflecting on the successes of ConnectinGEO’s work.

ConnectingGEO staff noted that the team created ENEON, developed a gap analysis methodology, studied the implementation of essential variables in GEO SBAs, and conducted an analysis of the relationship between the essential variables and the SDGs.

The importance of in-situ data measurements and the creation of a network devoted to compiling data and knowledge cannot be understated, they said.

“Many things you can only measure when measuring in-situ: on the ground, in a tower, with an ocean buoy,” McCallum said. “Remote sensing is done with satellites, which is also very important, because it allows you to scale up. That info needs to be calibrated (and validated) somehow. For that calibration you need these in-situ measurements. You need data from one location for calibrating and data from another location to validate what you’re doing. There are thousands of in-situ networks collecting a variety of different info. It’s about bringing all of that together to get a clear pic of what’s being measured where.”


Much of the work to create ENEON included old-fashioned networking. McCallum noted that the partners conducted surveys, attended conferences and workshops, and discussed with the European Earth observations community the need and process to build an understanding of the networks and the people needed to collect data.

The ENEON graph of in-situ Earth observation European networks shows a complex network. Image Credit: ENEON

ENEON is especially focused on the in-situ segment of Earth observations, which McCallum and ConnectingGEO staff said is perennially under-noticed and underfunded in comparison to remote sensing segments. Mapping the in-situ networks has led to the discovery of a large, complex and incomplete system with coordination within each topic, but less interaction and knowledge across topics.

ENEON was created to increase the connection between the existing European EO networks and the relevant communities engaged in the assessments, forecasting, and projecting of future developments: policymakers, European Commission, GEO/GEOSS, Copernicus, etc. ENEON is also a platform to promote emerging European networks and sensor development projects to provide future provisions, which may not yet be part of GEOSS or Copernicus Services.

ENEON is positioned to play a role in developing, validating, populating, and using the Socio-Economic and Environmental Information Needs Knowledge Base (SEE-IN KB) for virtual collaboration between providers, scientific and societal users, and decision- and policymakers. For this reason, an ENEON Virtual Marketplace/Commons was created the sharing and reuse of digital objects in a web space.


“One of the components of ConnectinGEO was to identify Earth observation gaps. We’re trying to do that in the context of these Societal Benefit Areas from GEO, but also trying to consider the Sustainable Development Goals, and essential variables,” McCallum said.

Dr. Hans-Peter Plag, professor of Ocean, Earth and Atmospheric Sciences and director of the Mitigation and Adaptation Research Institute (MARI) at Old Dominion University, added:“The work done in ConnectinGEO was to support the quantification of the SDG indicators and to support the policy development for SDG implementation with enhanced data and knowledge.”

McCallum noted that the table the group compiled by ConnectinGEO identifies more than 200 gaps. The project team used different methods to develop prioritized lists of gaps, which were communicated to the European Commission.

The gap analysis was done and interpreted by themes, gaps represented by threads of the methodology, gaps represented show by EVs, and also gaps by type. The following figure shows the result of the analysis of gaps by type.

“Related to the SDG implementation and monitoring, the lack of data on the built environment and the need for integration of traditional Earth observation data with socio-economic data were emphasized,” Plag said.

Gaps in in situ Earth observations showing analysis of gaps by types. The vertical axis is a count of the number of gaps detected.
Image Credit: ConnectinGEO


“The concept of essential variables (EVs) is increasingly used in Earth observation communities to identify and prioritize variables and observations that are key to the missions of these groups,” Masó noted.

Initial efforts to establish essential variables were made by the Global Climate Observing System (GCOS) under the UN Framework Convention on Climate Change (UNFCCC), which developed a set of Essential Climate Variables (ECVs). In addition, GEO provides a framework for the development of set of EVs for each SBA and thematic area, including Essential Ocean Variables (EOVs) for marine, chemical, and physical aspects of the oceans, and Essential Biodiversity Variables (EBVs) for biodiversity.

ConnectinGEO partners evaluated 147 potential essential values for in situ Earth observations, which helped the team recognize that, while the climate community has the highest number of essential variables, the weather and ocean communities are maturing. Of the other SBAs, development of essential variables in biodiversity, water, and energy follow. However, agriculture, disasters, ecosystems, health and urban development are still in the initial stages. Many of the essential climate variables are relevant to the other GEO SBAs or themes, and so many SBAs could rely on a number of EVs already available in other areas.


Because there is currently insufficient in-situ coordination across topic boundaries Europe and most other parts of the globe, there is no coordinated representation of the in-situ networks in GEO and GEOSS.

“An example illustrating the situation is the case of coastal observations, which are fragmented and unevenly developed among European Seas,” Masó wrote. “Although the data are public, little is done to publicize the data (e.g., high resolution bathymetry, fishery data) and integrated data portals are not available. From ConnectinGEO, we encourage this coordination and propose ENEON as a leading actor in this task.”

Many of the gaps the team identified are technological in nature, which leads to low technological feasibility for closing the gaps. There are, for example, essential variables for coastal ecosystems (pollutants, plastics, marine litter, dissolved substances), which are thwarted by a lack of operational observations. There are costs of maintenance operations and vandalism that affect the sustainability of the networks, as well as interruptions that make long time series data collection difficult.

In terms of logistics, the group has noted that communication and exchange of information would help the networks move toward standardization and accessible open data.

For in-situ observation, there are technical issues that need to be addressed, including quality check, improved access through interoperable data management systems, increased transparency for observation and processing methods, and improved documentation on usability and applicability. For satellite data, access, sharing and quality are issues deserving more attention.

Finally, there is a need to educate the public about the relevance and usefulness of Earth observations for the SDGs.


In the future, ConnectinGEO anticipates seeing its recommendations addressed through the work of ERA-PLANET Strand-2: Resource efficiency and environmental management of the Joint Transnational Call.

This is part of a series of NeXOS articles. The others are below:

This article was funded in part by the NeXOS project by Grant Agreement No. 614102 under the call FP7-OCEAN-2013.2 from the European Commission.

Kelley Christensen is IEEE Earthzine’s science editor. Follow her on Twitter @kjhchristensen.