Spatial attenuation study of the vibration sensed by DAS at different radial distances

In the underground environment, it is the most challenging for two-dimensional (2-D) localization of the ground-borne vibration sensed by the buried fiber cable, especially for the location estimation in the radial direction, due to the complicated inhomogeneous geophysical structure. Thus, in this paper, feature extraction and representation with the spatial power spectral distribution is studied for the fiber-optic distributed acoustic sensor (DAS), and the fundamental spatial attenuation law is discussed from the field results when the vibration source is located at different radial distances. The field test has proved that the spatial power spectral distribution can represent the differences at different radial distances well, which provides a promising way to improve the 2-D localization performance of the ground-borne vibration source sensed by the fiber buried in complicated underground environment.