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Beyond Locating - Resolving Unique Underground Utilities with a Handheld-Sized Stepped-Frequency Continuous-Wave (SFCW) GPR
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 1st Conference on Geophysics for Infrastructure Planning Monitoring and BIM, Sep 2019, Volume 2019, p.1 - 5
Abstract
Pulsed GPR has been the main GPR technology for more than 30 years. However, stepped-frequency continuous-wave (SFCW) GPR technology presents two documented advantages compared to pulsed GPR: a bandwidth wider than the typical definition of “UWB”, and an approx. up to 20 dB higher signal-to-noise ratio. This results in larger penetration depths and improved resolution without salt-and-pepper noise.
In late 2017, SFCW technology became commercially available for concrete, where a system with frequency range 0.2–4.0 GHz demonstrably delivers both better resolution and depth penetration without post-processing filters. Since 2018, the SFCW GPR instrument is increasingly used for locating shallowly-buried utilities, an application so far addressed with pulsed-GPR devices.
We collected SFCW GPR data in soil to investigate the reason behind this trend, revealing that the technology’s benefits extend beyond concrete.
The SFCW GPR system can not only detect closely-spaced utilities but also resolve them uniquely within a bundle as countable hyperbolas, within typical depths, even though it was not developed with this application in mind.
Thus, with SFCW GPR subsurface investigators receive information beyond a “dig / no-dig” decision and can deliver insights that improve BIM and increase clarity for all stakeholders of infrastructure planning, monitoring and maintenance operations.