Spatial coherency statistical model of ground motion

Based on parts of the earthquake records collected in SMART-I array and Chiba array, the spatial coherency of the ground motion components was studied among the frequency domain. Three coherencies??different components from different stations of the ground motion, same components from different stations and different components from the same station, were taken into account. The range and the cumulative distribution density function of the decoherence coefficient value for each case were determined through the statistical methods. Finally, a statistical model of the coherency function was presented.