On the possibility of increasing the signal-to-noise ratio by using the harmonics in non-explosive seismic exploration

In the Vibroseis method, along with the main sweep signal, its harmonics, which are usually considered as noise, travel into the Earth's crust. The natural information that can be extracted from the harmonics is the high-frequency component that is absent in the signal. However, even within the frequency range of the main sweep, it is possible to utilize the energy of the harmonics to improve the signal-to-noise ratio. It is shown that the conventional signature deterministic deconvolution loses the energy of the harmonics. At the same time, the optimal statistical focusing filter that accounts for the additive noise factor, successfully utilizes the energy of the harmonics.