Japan Geoscience Union Meeting 2024

Presentation information

[J] Poster

S (Solid Earth Sciences ) » S-TT Technology & Techniques

[S-TT36] Applying optic fiber sensing to earth science

Mon. May 27, 2024 5:15 PM - 6:45 PM Poster Hall (Exhibition Hall 6, Makuhari Messe)

convener:Kentaro Emoto(Graduate School of Science, Kyushu University), Takeshi Tsuji(Department of Systems Innovation, the University of Tokyo), Masatoshi Miyazawa(Disaster Prevention Research Institute, Kyoto University), Eiichiro Araki(Japan Agency for Marine-Earth Science and Technology)

5:15 PM - 6:45 PM

[STT36-P08] Test Observation and Analysis of Traffic Moving Objects and Traffic Anomalies on National Route Using Optical Fiber DAS

*Hiromitsu Nakamura1, Hiroyuki Fujiwara1, Shohei Naito1, Ken Sakurai2, Chisato Konishi2, Haruhiko Suzuki2, Naoto Ogawa2, Masaki Takebe3 (1.National Research Institute for Earth Science and Disaster Resilience, 2.OYO Corporation, 3.Mitsubishi Electric Software Corporation)

Keywords:optical fiber, Distributed Acoustic Sensing, traffic moving objects, traffic anomaly

It is possible to construct a real-time monitoring system using a dense optical fiber network that covers the city in three dimensions. In this study, as part of the urban monitoring, we report on the test observation of traffic moving objects and traffic anomalies using an optical fiber DAS installed along national route.
Observations using fiber-optic DAS were conducted on Route 6 and Route 50 starting in September 2023. Each measurement period was about 10 days. The instrument used for the observations was a Sintela ONYX. The measurement distances were about 57 km for Route 6 and 63 km for Route 50. The gauge length was 9.6 m, the channel spacing was 4.8 m, the optical pulse rate was 2 kHz, and the sampling frequency was 500 Hz. Video recording of vehicle traffic was also conducted in some sections.
To evaluate the possibility of detecting moving objects, video of traffic conditions was captured and temporally matched with DAS data. It was confirmed that the positions of the vehicles detected in the video generally matched the trajectory of the 2D display of the strain velocity measured by the DAS in both the temporal and spatial directions.
In trucks and passenger cars, there are differences in the magnitude of amplitude of some indicators, which may allow for a mechanical classification of vehicle types.
During the observation of Route 6, we observed changes in vibrations suggestive of vehicle accidents and traffic restrictions. The analysis of DAS data showed that it is possible to estimate not only the exact time and location of a traffic accident, but also the speed of the vehicle and the state of traffic congestion, based on actual data. In the future, it will be important to acquire DAS observation data under various environments and develop real-time analysis methods using these data for real-time monitoring of urban areas.
We thank Hitachi River and National Highway Office, Kanto Regional Development Bureau, Ministry of Land, Infrastructure and Transport for their cooperation.