Abstract
The presented topic contains the calculation procedures and the signals processing concepts used in the studies conducted in the presented report. The spatial variation of seismic ground motions is a phenomenon which regards the modification in terms of the frequency content and phase offset. This phenomenon assumes that the waves pass through soil strata that modify the arrival time of the waves. This idea is called wave passage effect. The incoherence of the waves is caused by the fact that when the waves pass through the soil, they encounter objects which determine them to reflect or refract from the main direction of propagation.