Geosensor: Semantifying Change And Event Detection Over Big Data

GeoSensor is a novel, open-source system that enriches change detection over satellite images with event detection over news items and social media content. GeoSensor combines these two orthogonal operations through state-of-the-art Semantic Web technologies. At its core lies the open-source, semantics-enabled Big Data infrastructure developed by the EU H2020 BigDataEurope project. This allows GeoSensor to offer an on-line functionality, despite facing three major challenges of Big Data: Volume (a single satellite image typically occupies a few GBs), Variety (its data sources include two different types of satellite images and various types of user-generated content) and Veracity, as the accuracy of the end result is crucial for the usefulness of our system. We present GeoSensor's architecture in detail, highlighting the advantages of using semantics for taking the most of the knowledge extracted from news items and Earth Observation products. We also verify GeoSensor's efficiency through a preliminary experimental study.