L.S. Chudnovsky1, M.V. Alyushin2

1,2 JSC “Precision Systems and Instruments” (Moscow, Russia)

2 NRNU “Moscow Engineering Physics Institute” (Moscow, Russia)

Formulation of the problem. The problem of searching for reflection times seismic signals at distances up to 1000 km is relevant both in geological exploration systems and in the analysis of earthquakes. A new method is proposed for their determination by the features of changes in the instantaneous frequency of the analytical signal during pulsed excitation of the oscillatory system.

Target. Consider the possibility of time the search for seismic signal reflections in a layered medium using the instantaneous frequency of the analytical signal. For segmentation, stabilization of the instantaneous frequency is used in the interval of free oscillations, when there are no effects of excitation pulses [5].

Results.  An estimate of the elastic radius of an acoustic radiator was obtained for the data of [1]. An analysis of the distances between the correspondents and the elastic radius of the acoustic emitter led to the conclusion that it was not an underground nuclear explosion in Nevada [1] that was registered, but a test signal for calibrating the Billings seismic system in Montana.

Practical significance. The specified method of analysis of oscillatory systems in the time sections of forced (action of the excitation pulse) and free (only oscillations of the system itself) sections allow more accurate assessment of the oscillatory characteristics of the system and analyze the phenomenological excitation pulses. The use of this method in the analysis of speech signals made it possible to obtain more compact distributions of primary transformations.

Chudnovsky L.S., Alyushin M.V. Instantaneous frequency of the analytical signal in the analysis of seismograms. Radiotekhnika. 2023. V. 87. № 4. P. 123−127. DOI: https://doi.org/10.18127/j00338486-202304-15 (In Russian)

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