The Design of a Web-Sensor Network for Environmental Monitoring and Remote Control Applications by Data Fusion Techniques

This paper proposes an innovative design of a Web-sensor network for environmental monitoring of the electromagnetic pollution. A remote control application allows to process acquired data and available information by an original data fusion procedure. The aim is to verify the compliance of the exposure levels to electromagnetic field with the limits established from law. The measurement system is a configurable network of wireless and smart Web-sensors distributed along an urban area. The implemented sensing units measure the electromagnetic field in high and low frequency ranges and, by General Packet Radio Service (GPRS) communication, acquired data are transmitted to WEB pages. By means of an original algorithm the whole area is divided in several local zones, where an equal number of sensors has the task to monitor specific zones. The clustering algorithm uses environmental and topographical information in order to configure the network and the monitoring map. So, the number and size of the zones are variable according to the desired resolution. A proposed Statistical Model allows to estimate the reliability curve over time of each sensor in order to get knowledge on its operating state. Starting from the available information, a remote workstation performs the data fusion procedure. Alarm and warning occurrences are singled out. A final report shows the zones which require greater attention so to plan suitable interventions on the area. Quality indexes provide indication on reliability and consistency of the result.