GeoPubSubHub: A Geospatial Publish/Subscribe Architecture for the World-Wide Sensor Web

Abstract

The World-Wide Sensor Web has become a useful technique for monitoring the physical world at spatial and temporal scales that were impossible in the past. With the development and deployment of sensor technologies and interoperable open standards, sensor web generates tremendous volumes of priceless data enabling scientists to observe previously-unobservable phenomena. By connecting various types of sensors located worldwide and performs observations at high-frequency, sensor web has the ability to capture time-critical events and provide up-to-date information to support efficient decision making. We argue that constructing sensor web infrastructure and applying interoperable standards are the first steps. In order to harvest the full potential of sensor web, efficiently processing sensor web data and providing timely notifications are necessary. Therefore, this research proposes GeoPubSubHub, a software component applying the publish/subscribe communication model to efficiently process geospatial sensor web data. In this thesis, we propose an overall system architecture to address the seven challenges identified for constructing a geospatial sensor web publish/subscribe system. In addition to the solutions that are similar to existing approaches, we propose sensor web input adaptor, LOST-Tree, semantic layer service, AHS-Model, and sensor web browser to address challenges that are most unique and critical in the context of a geospatial sensor web publish/subscribe system. Our evaluation results demonstrate that these proposed solutions can effectively address targeted challenges with efficient performance. As one of the first geospatial sensor web publish/subscribe systems, we believe that our proposed solutions and GeoPubSubHub architecture serve as a promising initiative to process sensor web data in a timely manner and will consequently harvest the full potential of the world-wide sensor web.