Dynamic Web Expression for Near-real-time Sensor Networks

Lindquist, K.G., R.L. Newman, A. Nayak, F.L. Vernon, C. Nelson, T.S. Hansen, R. Yuen-Wong

As near-real-time sensor grids become more widespread, and processing systems based on them become more powerful, summarizing the raw and derived information products and delivering them to the end user become increasingly important both for ongoing monitoring and as a platform for cross-disciplinary research. We have re-engineered the dbrecenteqs program, which was designed to express real-time earthquake databases into dynamic web pages, with several powerful new technologies. While the application is still most fully developed for seismic data, the infrastructure is extensible (and being extended) to create a real-time information architecture for numerous signal domains. This work provides a practical, lightweight approach suitable for individual seismic and sensor networks, which does not require a full 'web-services' implementation. Nevertheless, the technologies here are extensible to larger applications such as the Storage-Resource-Broker based VORB project. The technologies included in the new system blend real-time relational databases as a focus for processing and data handling; an XML->XSLT architecture as the core of the web mirroring; PHP extensions to Antelope (the environmental monitoring-system context adopted for ROADNet) in order to support complex, user-driven interactivity; and VRML output for expression of information as web-browsable three-dimensional worlds.