A Comparative Study of Seismic Characteristics Between Distributed Acoustic Sensing (DAS) and Geophones

In recent years, distributed acoustic sensing (DAS) has developed rapidly for characterization of geophysical properties. In comparison to conventional geophones, DAS utilizes fiber optic cables, relying on the phase-sensitive detection of backscattered light to measure strain changes caused by seismic waves, offering continuous and distributed coverage. In contrast, geophones are mechanical sensors that convert ground motion into electrical signals through the movement of a mass within a magnetic field. However, both technologies were used in similar application. In this paper, the use of DAS technology and conventional geophone was investigated and compared by using sledgehammer as active source. A linear fiber optic segment was placed alongside the conventional geophones in a designated testing location, and shot points taken at various distances are investigated. Data collected by seismic DAS and conventional geophones were analyzed based on their amplitudes and frequencies to measure their sensitivity. According to preliminary research, DAS has the potential to provide higher spatial resolution due to its continuous sensing capability along the optical fiber. Furthermore, DAS may reveal wave propagation characteristics similar to that of conventional geophones. This technology’s potential applications include the rapid deployment of active and/or passive arrays for near-surface geophysical characterization at various scales.