The network interoperability is ensured by a common set of standards so that data from different instruments can be combined into coherent datasets. This network is supported by the GEOSS Common Infrastructure (GCI) that provides catalogue, search engines and a GEO Portal that offers a single Internet access point for users search and discovery of data, imagery and analytical software packages to all parts of the globe. The GeoViQua FP7 project significantly contributes to this by adding rigorous data quality representations to existing search and visualisation GEO Portal functionalities, prioritising interoperability at all times.
Information about data quality is extracted from several sources; some of them are from metadata, data inter-comparison, validation processes towards in-situ sensor data, provenance information and from user feedback. Current or extended standards for data quality description are used or developed to define ‘ quality indicators ', including quality and provenance parameters as proposed by the GEO strategy on data quality, the “Quality Assurance Framework for Earth Observation” (QA4EO)”. GeoViQua combines geospatial data together with information on their quality and processing services within GEOSS catalogues.
Graphical representation of the metadata parameters helps the user to know the data collection structure and its patterns for easily screening the data. GeoViQua is contributing significantly to an enhanced, user-driven, and practical GEOLabel and thus allowing increasing user trustworthiness over GEOSS data and services delivery.
In GeoViQua a search broker supports filtering by quality parameters and sorting search results by quality indicator values. GeoViQua components address a variety of strategies for visualising data together with its quality information, on the GEO Portal. Query by location with metadata, quality statistical charts, and quality representations through symbology are some of the techniques explored. The components comply with existing standards to allow direct implementation in the GEO Portal as well as mass-market geo-browsers and mapping tools (such as Google Earth) and other 3D viewers.
Selected scenarios and use cases are present all along the different phases of the project, from the iterative collection and documentation of user and technical requirements, through the stages of system design and development, to the final system integration.
The Global Earth Observation System of Systems (GEOSS) aims to be a global and flexible network of content providers allowing decision makers to access an extraordinary range of information directly on their desk. It brings together existing observing systems around the world while supporting the development of new systems where gaps currently exist.