Comprehensive Evaluation of DAS Arrays in California: Instrument Response, Noise Level, and Amplitude Clipping

Qiushi Zhai, Jiuxun Yin, Yan Yang, James W. Atterholt, & Zhongwen Zhan

Submitted September 10, 2023, SCEC Contribution #13088, 2023 SCEC Annual Meeting Poster #052

Distributed acoustic sensing (DAS) is an emerging technology that converts optical fibers into dense arrays of strainmeters. However, the amplitudes in DAS recordings haven't been fully quantified, especially for pre-existing telecommunication cables with uncertain fiber-ground coupling. By calibrating three California DAS arrays with co-located seismometers, we systematically assessed their performance. Our results indicate that the average DAS amplitude of earthquake signals aligns with seismometer data, exhibiting fluctuations within an order of magnitude across channels and frequencies from 0.01 to 10 Hz. The noise level of DAS, crucial for detecting weak signals, is comparable to strong-motion stations within this frequency range but surpasses broadband stations below 1 Hz. The clipping amplitude of DAS, essential for capturing strong signals, can be adjusted using ping rate and gauge length, but this comes with trade-offs in data quality. Our comprehensive evaluation highlights the potential of DAS amplitude data in seismic studies.

Key Words
Distributed acoustic sensing (DAS), Instrument Response, Noise Level, Amplitude Clipping

Citation
Zhai, Q., Yin, J., Yang, Y., Atterholt, J. W., & Zhan, Z. (2023, 09). Comprehensive Evaluation of DAS Arrays in California: Instrument Response, Noise Level, and Amplitude Clipping. Poster Presentation at 2023 SCEC Annual Meeting.

Related Projects & Working Groups
Seismology