Seismic noise subsoil in order to draw seismic microzonation maps showing the predicted ground response to earthquakes. Research on the origin of seismic noise indicates that the low frequency part of the spectrum (below 1 Hz) is due to natural causes, chiefly ocean waves. In particular the peak between 0.1 and 0.3 Hz is clearly associated with the interaction of water waves of nearly equal frequencies but opposite directions. At high frequency (above 1 Hz), seismic noise is mainly produced by human activities such as road traffic and industrial work; but there are also natural sources, like rivers. Around 1 Hz, wind
Multidimensional seismic data processing seismic profile. This involves gathering seismic traces from points at the same depth and summing them. This is referred to as "Common depth-point stacking" or "Common midpoint stacking". Simply speaking, when these traces are merged, the background noise cancels itself out and the seismic signal add up, thus improving the SNR. Assuming a seismic wave formula_27 travelling upwards towards the surface, where formula_28 is the position on the surface and formula_29 is the depth. The wave's propagation is described by: formula_30 Migration refers to this wave's backward propagation. The two-dimensional Fourier transform of the wave at depth formula_31 is given