Ground Penetrating Radar (GPR) is a non-destructive detection technique that uses high frequency radio waves to evaluate natural or manmade features buried deep in the ground.
The mining and archaeological industry has long been using this geophysical technique to probe for deep objects and resources underneath the ground surface. Despite the current GPR profiling up to around 300 meters, many new techniques and applications have been discovered particularly in the site investigation field. Some of these new applications include concrete scanning and investigation, locating cables and pipes in urban areas, military use (detecting landmines and buried explosives) and many others.
So, how exactly does a GPR work?
The Ground Penetrating Radar technique passes high frequency radio waves through an antenna into the ground. The GPR antenna is pulled by hand or with an ATV or vehicle along the targeted location as it records reflected waves from different objects below the ground surface. Data from reflected waves is recorded in a digital control unit as color bands.
The GPR shows a cross-section profile from the ground surface to the deeper subsurface materials up to certain depths. The depth of a GPR’s profile will vary according to frequency, which ranges from 200MHz -1.5GHz. Objects located beneath the ground surface have varying reflections and since the device records each reflection with a distinct color, a nice 3D visualization can as well be extracted from the data.
GPR is a good technique especially in underground investigations. It can detect buried non-metallic objects such as water pipes and fibre-optics as opposed to some radioactive techniques. The GPR shows, with high accuracy, the exact location and depth of buried objects.
Technology can be very useful, in this case in locating underneath objects. Ground Penetrating Radar has advanced subsurface investigation to a better position, providing people easy and non-destructive methods of identifying underground objects and resources.