Mathematical model of seismic signal, as a flow of physically non realizable single seismic waves

• Дата: 2016
• Автори: Mostovoy, V. S., Mostovyi, S. V.
• Формат: Стаття
• Мова: English
• Опубліковано: Subbotin Institute of Geophysics of the NAS of Ukraine 2016
• Теми: seismic signal; stochastic flow; a posterior probability; seismic background noise; mathematical model
• Онлайн доступ: https://journals.uran.ua/geofizicheskiy/article/view/107830
• Назва журналу: Geofizicheskiy Zhurnal

The new conception of seismic data analysis is proposed. It is based on preliminary studying of seismic background. Its characteristics are a base for using mathematical models of non realizable seismic signals. The specific mathematical model of the seismic signal is proposed as well. The peculiarity of the model is that it allows you to simulate the flow of seismic waves of different classes each of them appears in the stream with specific time delay. This process takes place against the micro-seismic background noise. It is natural to model the flow of signals by the physically realizable signal. It means those signals which do not have a trace in prehistory. But this representation of the signal is unacceptable for two reasons. The first one is related to the smoothness of the signal at the time of its appearance on the seismic record. The second one is related to the fact that the fade of the signal in the noise does not allow us to determine the time of its appearance on the record accurately. The latter circumstance does not leave us the possibility to simulate the time of the signal occurrence by using the determined value. Therefore, the time of occurrence of the signal is simulated by random variable with variance depending on the level of micro-seismic background. We introduce the notion of generalized seismic signal as a function of time and of the vector of parameters, which  determine its shape, the energy, the place in flow of the other signals, spectral characteristics, and in general behavior in the entire history of its existence. Any widely spread seismic signal models used in practice are a particular case of this one. Or in a more rigorous approach to the definition the different  particular cases of the signals classes are transformed into the different hyper-planes into space of parameters.