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| | Abstract | | Distributed acoustic sensing (DAS) technology is a new method to measure ground rolls using an optical fiber and has been recently applied for CCS monitoring, VSP and surface wave survey. DAS do not require special optical fibers and can reduce monitoring cost for a long distance. However, conventional technologies require relatively longer gauge length over 1 m, which affects not to detect surface waves with short wavelength. This report shows results including conditions with smaller gauge length to consider capability of DAS for shallow exploration. DAS can acquire surface waves using optical fibers set in a plastic pipe, which can reduce cost to use standard communication lines previously set in the ground. Dispersion curves are analyzed from DAS records, which are similar velocities to that analyzed from surface wave records acquired with 4.5 Hz geophones of a vertical component. |
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