ESA’s Earthnet Data Assessment Pilot (EDAP)
Paving the way for New Space Players
For over 40 years ESA's Earthnet Programme has played a significant role as part of ESA's mandatory activities, providing the framework for integrating non-ESA missions, i.e. Third Party Missions (TPM), into the overall ESA Earth Observation (EO) strategy. Complementary to ESA-owned EO missions, the programme allows European users access to a large portfolio of TPM and is particularly important for promoting the international use of EO data.
In line with the Earthnet Programme objectives, ESA aims to foster cooperation and collaboration with not only other national space agencies, but also commercial mission providers. In recent years the availability of low cost small satellites and the innovation of constellations have resulted in an increasing number of commercial companies who have established business models to provide information services fed by their own satellite systems.
These New Space players are now playing an important role in the EO international strategy. Some of these new missions are potential candidates for Earthnet TPMs and ESA have therefore set up a project to assess the quality and the suitability of these missions and also to establish dialogues with the various mission providers in order to improve the overall coherence of the EO system; this project is known as the Earthnet Data Assessment Pilot (EDAP).
EDAP Missions & Studies
The key objective of ESA's EDAP is to take full advantage of the increased range of available data from non-ESA operated missions and to perform an early data assessment for various missions that fall into one of the following instrument domains:
This early data assessment is intended to provide some indication of the potential of each existing mission to remain as a TPM and for new and future missions to become TPMs within ESA's Earthnet programme. Furthermore, EDAP also places an emphasis on multi-mission studies that may span several instrument domains; such studies contribute to interoperability across existing and future missions and help foster synergies between these missions.
The EDAP project has defined a set of ‘best practice' guidelines defining a framework for the quality assessments it performs, aligned to the principles of QA4EO.
The EDAP consortium is headed by Telespazio VEGA UK and includes various clusters of expertise from within the industry.
The importance of the early data assessment is also to give confidence to EO data users and allow them to decide if the data is fit for their purpose. This activity requires specific instrument group domain knowledge and familiarity of the data processing algorithms to assess the quality performance of data products.
The team structure has been specifically tailored to address the unique characteristics of this service, but has also been influenced by the consortium's successful involvement in other similar projects and service contracts, such as inter-comparison exercises.
Quality Assurance Framework
Framework for EO Data Quality Assessment
A generalised framework for assessing the fitness of purpose of EO data is difficult to obtain as this would clearly depend on the users intent; however, there are key characteristics that give confidence to a user and allow them to decide if the data is fit for their individual purpose.
In particular, users wish to understand data coverage, data provenance, data characterisation, data availability and also data correctness. Each of these factors, given a different weighting by each user, can ultimately affect a user's opinion of how good the data is.
EDAP aims to address both data integrity and data credibility for the various missions identified, which may go on to become TPMs within ESA's Earthnet Programme.
The Quality Assurance Framework for Earth Observation (QA4EO) was created and endorsed by CEOS explicitly for the purpose of providing guidance on EO quality assurance so that data users are able to trust the data / information they are provided with is fit for purpose and fully interoperable with other datasets from both satellite and in-situ providers.
As there is potential for some commercial missions to become TPM candidates, for the most efficient exploitation of EO data, assessment of data quality, calibration and validation are indispensable tasks and also form the basis for reliable scientific conclusions. It is for this reason that one of the core functions provided by EDAP is focused on data quality, with an emphasis on the adoption of QA4EO guidelines.