Study on the Influence of Airgun Excitation Conditions on Airgun Signals and Travel Time Variation Measurements

摘要

Because of the different excitation conditions of the airgun source, there will be subtledifferences in airgun signals. Travel time variation of airgun signals often mix into source information which can't fully reflect the evolution of the medium. This article uses theairgun signals from the Binchuan Transmitting Seismic Station to analyze the airgun signal′s characteristics of phase and correlation. We conducted a comparative analysis of the effects of the pair difference method and the deconvolution method on eliminating the influence of the excitation conditions in travel time variation. The results show that: (1)The pressure pulse and its subsequent wave of airgun source wavelet are less affected by excitation conditions that we can use it to obtain high-precision excitation moments. (2)Deconvolution can improve the correlation of the airgun signal. (3) The pair difference method can't eliminate the influence of excitation conditions in travel time variation.Deconvolution can reduce excitation condition interference and the influence of the excitation condition in the travel time variation after deconvolution of the vertical signal is significantly reduced.