Estimation of the Spatial Resolution in Acoustic Investigation of Ground Layer

摘要

Abstract Calculation relations are derived for analyzing the possibility of detecting local inhomogeneities by the method of reflected waves when carrying out acoustic investigation of the ground layer. The amplitude value of the total response at the receiving antenna output is represented as a two-dimensional terrain—a function of two arguments: delay time of the back-reflected pulse echo signal and the aperture center displacement during spatial scanning relative to the place of the intended localization of the inhomogeneity. Based on a graphical representation of the total response of the receiving antenna in the form of a two-dimensional space–time terrain, the feasibility of the proposed method for detecting local inhomogeneities proposed method of detection local inhomogeneities in the probed medium is demonstrated. The illustrations of the results of mathematical and numerical modeling clearly show that this approach helps in obtaining information about the actual profile or nature of the horizontal spatial distribution of the anomaly. The influence of the duration of the probing pulse and the aperture of the receiving antenna, the size and depth of the local inhomogeneity, as well as the dissipation factor, during the propagation of seismic-acoustic waves on the resolution in probing and remote diagnostics of inhomogeneity parameters is analyzed by mathematical and numerical modeling. The field of application of the developed technique is engineering seismic exploration of karst cavities, breccias, caverns, and other types of local inhomogeneities.