English to Russian Tech/Engineering Geology Сейсморазведка

Mathneey and Nowack proposed an instantaneous frequency matching method, which is to use an iteration process to modify a causal attenuation operator, so as to make weighted instantaneous frequencies by the operator acting on an envelope peak after a reference pulse and on an envelope peak of a target pulse closest, thereby inversing a quality factor of a medium. Adopting this method, Mathneey and Nowack estimated the attenuation of the seismic data on earth crust diffraction. Dasios et al. estimated the attenuation of a full-wave train acoustic logging record by adopting an instantaneous frequency matching method. Such method overcomes some shortcomings of the logarithmic spectrum comparison method, for example, it is not necessary to select a variable frequency band range and so on. However, this method needs to use a Hilbert transform method to calculate the instantaneous frequency, and to use a complicated iteration process to match the instantaneous frequency. As is well-known, the Hilbert transform is sensitive to noise; therefore, the use of the instantaneous frequency matching method in a seismic signal with noise is limited. Barnes assumed that a seismic source sub-wave is an ideal band-pass sub-wave, and gave a relationship between the instantaneous frequency and the Q value as well as the transmission time, but the practical seismic source sub-wave is greatly different from the ideal band-pass sub-wave.

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