Estimation of Infrasound Source Positions using Multipoint Observation
* Presenting author
Infrasound can be excited by dangerous global phenomena such as tsunamis and volcanic eruptions. Because infrasound travels in the atmosphere significantly faster than tsunami gravity waves, early detection of tsunamis can be achieved by monitoring this infrasound. To accurately identify a tsunami source (i.e., the position of the infrasound source), it is important to use numerous sensors distributed with long baselines. We developed a low-cost infrasound observation device using micro-electro-mechanical system based atmospheric pressure sensors. To test its usability, indoor and outdoor tests were conducted using multipoint observations. In the indoor experiments, the infrasound was excited by opening and closing a door, and by bursting a large balloon. The accuracy of time synchronization was examined by positioning infrasound observation devices at different points. The results showed that the time errors were within one sampling time (10 ms) in nearly all the indoor conditions. In the outdoor field test, infrasound excited by the explosion of fireworks during a festival was observed at multiple points in Sendai, Japan. The results showed that the source positions can be estimated with reasonable accuracy. This suggests the suitability of the device to estimate the source position of tsunami-scale earthquakes.