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Session: Sensing Technologies and their Latest Developments [Poster]

Type: Poster

Date: 10/7/2024

Time: 05:00 PM

Room: Stanley Park Ballroom

Amplitude Calibration for Distributed Acoustic Sensing

Distributed Acoustic Sensing data is increasingly used to characterize near-source and far-field signatures of anthropogenic and natural sources. However, conversion from strain rate to particle velocity can be challenging in environments where near-field elastic properties and fiber coupling affect the recorded DAS signal. Calibrated signal amplitudes are critical for wavefield modeling efforts and quantitative interpretation of DAS data. We compare amplitudes of controlled-source signals, ambient noise, explosions, and earthquakes recorded on co-located fiber optic and nodal instrumentation and discuss optimal approaches for converting strain rate to ground motion. Variations in fiber geometry, emplacement, and signal frequency are analyzed to derive transfer functions between fiber and geophone data for different fiber arrays and source types. We show that while empirical relations for converting strain rate to acceleration are useful as a first order approximation, using a gradiometry-derived strain rate provides a more useful comparison. These results will inform future applications where well-calibrated amplitudes are required. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.

Presenting Author: Christian

Additional Authors