Ground Penetrating Radar (GPR)
GPR is a geophysical tool that transmits electromagnetic waves into the surface and records the reflection of that wave off of contrasting electrical properties of buried materials. This technique offers high resolution, rapid imaging, and can provide depth estimates to targets; so it has a huge variety of applications. One of the strengths of GPR is that it can identify non-magnetic targets. From locating inch wide utilities held within concrete to mapping bedrock depth this technique is extremely versatile!
Some Applications:
Locating metallic and non-metallic buried objects such as utilities (including HDPE/plastic lines), pipes, drums,
Engineering applications including void detection, concrete imaging(rebar and PT cable), foundation investigations, and bridge corrosion detection
Railroad analysis - railway channel analyses
Depth to bedrock and soil layers (stratigraphy)