[M-TT50] Distributed Fiber Optic Sensing for Geophysical Applications

[MTT50-P02] Lessons learned from dark fiber distributed arrays in a large urban campus

*Dante Fratta¹, Herbert F Wang¹, Neal Lord¹, Shreeshrita Patnaik¹, Agatha Podrasky², Alexander Malamet¹, Paul Barford¹ (1.University of Wisconsin Madison, 2.Silixa Ltd.)

Keywords:distributed acoustic sensing, geophysics

We have deployed a distributed acoustic sensing (DAS) array using dark fiber across the urban campus of the University of Wisconsin-Madison. During two weeks, a Silixa iDAS interrogator was used to target campus traffic, railway activity, commercial movements across busy thoroughfares, sporting events, and a carillon concert. These events were captured on the DAS array and used to assess the performance of dark fiber for the deployment in city-wide and regional monitoring systems. This deployment faced challenges related to the mapping of the cable, the coupling of the optic fiber to conduits and near-surface ground, and multiple sources from different locations acting simultaneously. The lessons learned from these studies can be used to develop a better sensing array and make greater use of existing communication infrastructure.