No, It’s Not a Fancy Metal Detector: The Uses of GPR

two images of gpr scanning devices

We like to think of ourselves as ground penetrating radar aficionados. We’re more than just utility scanners. We’re a team that’s truly passionate about the technology, and we die a little inside every time we hear someone say, “GPR is just a fancy metal detector.”

The uses of GPR are far more powerful than those of a metal detector. It’s a powerful and innovative technology that presents numerous possibilities. And yes, it also has its limitations.

We wanted to take an opportunity to share a little about GPR technology, including some history, different GPR uses, and the current limitations of ground penetrating radar technology.

The History of Ground Penetrating Radar: Ice Sheets in WWII

Before we talk about history, let’s talk about the technology. Ground penetrating radar uses electromagnetic waves to penetrate a substrate and produce reflections of what’s beneath the surface. In simpler terms, GPR allows us to look beneath the surface and see what’s going on below.

Most people are surprised to learn that ground penetrating radar technology has been around since the 1930s! It was originally developed to measure the thickness of ice glaciers. The technology continued to evolve throughout the 60s and 70s, and by the 1980s GPR equipment was more affordable and started to become more widely used.

Since then, the technology has continued to improve, extending the uses of GPR dramatically. Let’s take a look.

The Top Uses of GPR

If you were to look at a scatterplot graph of the different uses of GPR, the applications would be heavily concentrated on utility locating and concrete scanning. It’s used most often in the AEC industry (architecture, engineering, and construction). Still, GPR uses extend beyond the AEC space, too. 

Some of the uses of GPR include:

  • Utility Scanning – searching beneath the surface for public and private utility lines (aka public and private utility locating).
  • Concrete Scanning – looking inside concrete for rebar (aka rebar verification), post-tension cables, voids, and more.
  • Down-Borehole Radar – with a different type of GPR antenna, GPR can also be used to investigate drill holes or uncased borings.
  • Moon Investigation – one of the coolest GPR uses! GPR equipment was sent to the moon on a lunar mission to investigate the subsurface of the moon.
two gpr scans from the surface of the moon
The landing region and route of the rover carrying a GPR antenna on the moon, via
  • Thickness Determination – GPR can be used to determine the thickness of a target or material, like ice sheets, underground tanks, and more.
  • Bathymetry – GPR can be used to determine a depth profile for a lake, river, or other body of freshwater.
  • Archaeology Scanning – GPR can be used to help locate archaeological findings, especially when digging might destroy something important.
  • Paleontology Scanning – GPR can be useful when searching for bones beneath the surface (like locating whale bones with GPR).   
  • Bedrock Investigations – The uses of GPR also extend into geology to gather data about the various sediments.
  • Police Investigations – Police officers can use GPR to search for different types of buried targets.
  • Forensics Investigations – Ground penetrating radar can be helpful in finding unmarked graves.

Yep, there are a lot of uses of GPR. But the technology does come with some limitations.

Some Common Misconceptions About Ground Penetrating Radar

We may loathe ground penetrating radar being compared to metal detectors, but a bigger pet peeve of ours is when we hear “experts” overselling the capabilities of GPR or touting misconceptions.

Yes, ground penetrating radar is an amazing technology, but it’s essential to be aware of its limitations.

For example, GPR uses do NOT include:

  • Bathymetry in saltwater (freshwater only)
  • Searching for gold (it’s impractical to use GPR for a wide, unfocused search)
  • Locating small PVC water pipes (there’s usually not enough dielectric contrast)
  • High-altitude (more than 1 meter AGL) drone-launched investigations (a large percentage of the strength of the electromagnetic wave attenuates at the air-ground interface; not to mention the legal concerns with such a flight in the USCanada, and Europe)

GPR technology is advancing and regulatory environments are changing all the time. So, while these things may not be possible today, it may just be possible to do these things and more in the future!

Getting Started with Ground Penetrating Radar

As you can see, there are many exciting GPR uses, and we get excited about all of them. We’re professionals in underground investigations and finding the unfindable. Our technicians love to put our ground penetrating radar knowledge to work. But we will also never over-promise or oversell the capabilities of this technology.

If you’re interested in learning if ground penetrating radar is right for your project, contact us today.

Give us a call: 951-783-2483