Earth Science as an e-Infrastructures Application: Practices at the ESA

Earth from Space
Earth Observation (EO) monitors the status of natural and built environments, gathers information about our planet’s physical, chemical and biological systems. Earth observations cover both space and time and
provide fundamental input into earth sciences. Example applications include:
• preventing geohazards (floods, earthquakes, tsunamis, volcanoes, etc.)
• measuring land-use (deforestation, urban expansion, etc.)
• tracking biodiversity (oceanography, carbon cycles, etc.)
• monitoring climate change
• forecasting weather

Satellite acquisitions: data management issues and requirements
The quality and quantity of Earth observations is increasing rapidly with the launch of new satellites and technological advances. As an example, around 150 terabytes of EO data was archived during ‘90s, with about 20 petabytes expected in the next 10-15 years. The ESA has excellent contacts within the earth science and EO communities, allowing the most urgent requirements for EO data dissemination and exploitation (for example, in the management of geohazards and climate change) to be identified. Needs within different communities also differ. For example, geohazards experts want standardised and interoperable access to distributed data and sensors, while climatologists are increasingly focused on access to historical data archives. EO data archives extend back from a few years to decades and have considerable value in the study of global change. It will be soon necessary to re-analyse, on a global scale, the climate information currently locked inside large thematic archives. Major application areas include the environment (forest, soil, urban development, air quality monitoring), civil protection, and disaster monitoring. Such long term monitoring of the Earth’s environment will enable a reliable assessment of the global impact of human activity and the likely future extent of climate change.

Increasing Earth Observation take-up
As well as supporting operational EO-based services under the Global Monitoring for Environment and Security umbrella (www.gmes.info/), the ESA are also working to address the above requirements using a wide range of conceptual and technological solutions, from applying new data dissemination strategies to data preservation and (re-)processing.
Solutions for dealing with these large data volumes include both cloud computing (on-demand procurement of IT capacity) and grid computing, technologies that allow for simultaneous large scale data sharing (especially useful for those concerned with geohazards, who may have real-time constraints) and tailored data processing services (allowing user-specific processing of raw digital data from satellites, for example.)

The ESA is working with all European EO data owners to identify long-term data preservation needs, with attention to archives maintenance and operation; data integrity, security, access, interoperability and reprocessing; data exploitation and standardisation. As a result, the ESA has established and now coordinates the European framework for the long-term preservation of EO data. The ESA works to increase EO take-up by encouraging the development of new applications and services centred on user needs, supporting projects aimed at optimising the accessibility and use of the EO data (>5000 projects have free access to data), and actively promoting the adoption of innovative IT solutions.

ICT Infrastructures for eScience
These solutions can converge and co-operate in the same ‘virtual’ environment, meeting the European Commission (EC) definition of an ‘e-Infrastructure’, i.e. ‘an environment […] where resources can be readily shared and accessed […]’.
In this context, the ESA also participates in a number of EC-funded projects, sharing best practices with its user communities and other international organisations. For example, the ESA participates in D4SCIENCE (www.d4science.eu/), GENESI-DR (www.genesi-dr.eu/), CASPAR (www.casparpreserves.eu/), and PARSE (www.parse-insight.eu/); these projects focus on e-solutions for the earth science domain and have made important steps towards enhancing access to quality scientific information.