Estimation of earthquake ground motion by image analysis of sliding objects taken with a fixed camera

This paper proposes a method to estimate earthquake ground motion by analyzing the video taken with a fixed surveillance camera. In recent years, a network of seismometers was constructed to observe the ground motion. However, the spatial density of the seismometers was not high enough to obtain an adequate spatial distribution of the earthquake ground motion, which varies depending on the local ground condition across tens or hundreds of meters. To interpolate the network of seismometers, we propose a method to estimate earthquake ground motion by using a fixed surveillance camera. In our method, the motion of objects sliding on the ground or on a floor is estimated by image analysis. Then, the earthquake ground motion is obtained by inverse analysis of the sliding motion. We conducted scale model experiments to evaluate our method, and the experimental results show the effectiveness of our method.