ArchaeologyData CollectionData InterpretationSensorsUtility Locating

3 Reasons Why You Can’t See Your Target With Ground Penetrating Radar (GPR)

By November 18, 2016 4 Comments

In this video I discuss three reasons why you might struggle seeing your buried target with ground penetrating radar.

First, you could have the wrong antenna frequency.

Second, you might be working in poor soils and your signal diminishes before it can reach the depth of your target.

Finally, there might be too little of a contrast between your target and the material it is buried in.

A few weeks back I dealt with a common GPR survey problem in another video showing how GPR practitioners can use disturbed soil to identify a buried target even if they can’t see the actual target itself with the ground penetrating radar.

CLICK HERE to see the video!

So here I wanted to show why you might struggle.

Enjoy!! is an online training platform for Ground Penetrating Radar that helps civil engineers, utility locators, and others learn about GPR through fun and engaging courses and coaching.

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Join the discussion 4 Comments

  • Hey Dan, ….not being able to locatie the target….?
    Hmmmm, The Netherlands is one big box of clay.
    With lost of peat.
    With high groundwatertable (brakish near the coast).
    Densely populated, i.e.buildings/disturbances.

    So, when I’m not able to locate what I want it’s mainly due to number 2.
    In the back of my car , I carry several antenna’s with me (exit nr.1). Or often make combinations with MAG/EMI etc.

    And hope for the best 😉

    • dpbigman says:

      Hi Ferry,
      Thanks for the comment!
      Your situation sounds much like mine. In Atlanta, GA the conditions can be brutal.
      You bring up an important point though, I often pair survey with Mag/EMI.
      The ability to identify completely different properties is super helpful (OKAY…EMI does work on some similar properties).
      No single best tool, context is KING!!!
      Thanks again.

  • Ron Kaufmann says:

    Hi Dan. Nice website and videos!
    Another reason not finding a target with GPR is “not being able to see the forest for the trees”. Geologic anomalies due to different sources will often look similar. For example, diffractions from a void in limestone will look similar to diffractions from the pinnacle nature of young limestone. This is especially evident in areas with shallow, young limestone like in South Florida and the Bahamas. Geophysical consultants not familiar with such geology will often pick out every diffraction as a void anomaly when in reality they are picking anomalies from the irregular limestone surface. Signal polarity analysis can be especially helpful in discriminating anomalies in such conditions, but even that can be misleading. As you mention, it is often best to pair the GPR with multiple geophysical methods to develop the best assessment of subsurface conditions.
    Keep up the interesting videos

    • dpbigman says:

      Hi Ron,

      Thanks for the comment and I appreciate you building on my answer. So true especially for geology. I think since I work in the ultra near surface so much I forget to tie you all in. But absolutely it can be difficult to determine geological structure, especially for practitioners without a background in geology (and sometimes for folks with background in geology). Please keep watching and commenting. It’s great when others add things I miss and enhance the conversation and learning.