Virtual Knowledge Graphs over Earth Observation Data

Earth Observation (EO) data publication and dissemination continues to grow driven by the increase in satellite launches. openEO is one of the most well known platforms to query EO data (in the form of datacubes) using web APIs. To be truly valuable, EO data often needs to be combined with other data sources, notably relational databases. Knowledge graphs offer a way to bridge the semantic gap between EO data and these additional sources. However, the execution of integrated queries can run into scalability issues due to the enormous volume of EO data. In this paper, we propose addressing this challenge through the use of Virtual Knowledge Graphs — a paradigm that presents data to end-users as a knowledge graph, while keeping the data in its original sources rather than materializing it in graph form. We show the feasibility of our approach by implementing a prototype solution and test it over real world openEO examples.