A new infrasound sensors array system, based on optical fibre transmission, has been realized to monitor the explosiv activity of the Etna volcano. The system is composed by an 8 channels receiver central station, recording data from 4 low power sensor nodes, measuring the following parameters

• Infrasound signal (16 bits).
• Temperature (1°C accuracy).
• Voltage of battery (8 bits)

The Etna infrasound network has a “star” configuration, organized in 4 stations, working like “antennas” to provide in
real-time the propagation azimuth of the sonic beam. According to the geometry of the array it’s possible to resolve the infrasound source position by grid searching algorithm calculating in real-time the cross-correlation between the single station. The infrasound signal, acquired by a microphone, is filtered by an active, low noise, 5 order, 20Hz low pass filter, then it is acquired by a 16 bit ADC at a rate of 50 samples/sec. The user can set an amplification factor of 0,1/0,5/1/10.

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News by Ciamberlini Claudio