WiFi data transmission system for monitoring volcanic areas: an example application on Mt. Vesuvius

摘要

The Seismic Monitoring Network of Mt.Vesuvius, managed by Istituto Nazionale diGeofisica e Vulcanologia, sezione di Napoli, Osservatorio Vesuviano (INGV-OV), currentlyconsists of 13 analog short period stations (9 single component and 4 triaxial),2 digital broadband stations and a permanent seismic array (composed of 16 triaxialsensors). Moreover 2 dilatometers are installed in the area, that are integrated in theseismic monitoring system.The distance among the station and between each station and the data acquisitioncenter varies from hundreds of meters to some kilometers. Part of the data is collectedin local Data Acquisition Centers (CAD) and then centralized at theMonitoring Centerof INGV-OV.In recent years, information technology has become fundamental in seismic networksand geophysical instrumentation, this includes also the data transmission systems. Inthis context, the new standards for wireless networks has proved to be a useful tool forthe transmission of geophysical data. This is the reason why we have chosen to adoptthe Wireless Fidelity transmission system, based on available frequencies typical ofthe IEEE 802.11h standard, which allows high capacity data traffic.We have realized different local area networks based on WiFi technology. They canoffer a coverage to high density traffic with extensions varying from a few dozen ofmeters to kilometers. Each network can be connected through a concentrator device,called access points, and a base station, through a high-capacity system of geographicconnectivity, which will be responsible for the liaison to the Monitoring Center ofINGV-OV, where seismic data are centralized. There the data are acquired and analyzedby automated systems, that produces parametric information in real time.The architecture of local networks and the backbone for data transmission has beendesigned to allow a modular development that is well suited for the needs of continuousimprovement of the network and the introduction of new systems for geophysicaland geochemical volcano monitoring. Currently the infrastructure manages a total of79 channels with a 24-bit at 100 cps sampling, but the network has a much greaterpotential. So the future transition of the seismic network from analog to a fully digitalequipment will be supported by this data transmission system.