STUDY OF AMPLITUDE-FREQUENCY CHARACTERISTICS OF EXPERIMENTAL DATA OF DEEP GPR DATA COLLECTED IN PERMAFROST
O.A. Gulevich, L.B. Volkomirskaya
Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences,
Moscow, Russia
Keywords: GPR, amplitude-frequency analysis, deep GPR, electromagnetic CDP, amplitude-frequency characteristics, AFC
Abstract
This study analyzes the amplitude-frequency characteristics (AFC) of deep GPR data gathered using variable offsets within the permafrost of the Nadym District, Yamalo-Nenets Autonomous Okrug. The initial frequency response of the raw data, which underwent only basic pre-processing, is presented, evaluating the effects of transmitter-receiver separation (100–750 m) as well as the spatial and depth-based placement of the analysis zone. This approach reveals the spectral evolution of electromagnetic signals within the geological environment during the late stages of the process. Results indicate that as the distance from the source increases, the signal undergoes standard attenuation, alongside three primary spectral effects: a downward frequency shift of the peak amplitude, a narrowing of the spectral bandwidth, and a significant rise in low-frequency components—the latter being primarily attributed to zero-line drift. Adopting spectral analysis techniques from seismic exploration for deep GPR data is a promising way to refine data processing and improve subsurface interpretation.
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