Developing a distributed acoustic sensing seismic land streamer: Concept and validation

Motivated by existing cabled seismic land-streamer designs, we develop a distributed acoustic sensing (DAS) land-streamer system for high-resolution near-surface seismic data acquisition. The system consists of a DAS interrogator unit (IU), a fiber-optic cable attached beneath a fire-hose assembly for environmental isolation and improved fiber-ground coupling, and a vehicle-mounted accelerated weight-drop source. The DAS land streamer is easily deployed and towed along the ground surface, allowing for spatially dense data acquisition. We report two field tests with the developed hardware to evaluate the DAS land-streamer performance. The first test investigates the effects of hose weight on the surface-deployed fiber and indicates that this approach improves fiber-ground coupling and leads to an improved signal-to-noise ratio (S/N). The second test demonstrates that the DAS land streamer records waveforms with similar phase and moveouts as those recorded by horizontal geophones but offers a higher native spatial density advantage than standard geophone arrays, leading to spatially dense waveforms, improved S/N after postprocessing, and superior surface-wave acquisition array mobility. Our findings suggest that a DAS land streamer is a promising alternative to traditional geophone-based surveys and may offer several advantages, such as faster survey acquisition speed and lower field costs due to reduced acquisition hardware requirements. However, methodological limitations include recording a single horizontal ground-motion component, a dependence on favorable fiber-ground coupling conditions, and the upfront cost of IU procurement. A DAS land streamer may be useful in numerous subsurface applications, such as (pseudo) 1D multichannel analysis of surface waves or 2D surface-wave inversion for S-wave velocity model estimation for geophysical, geologic, geotechnical, and environmental investigations.