Utility Scanning
Soils Ground Penetrating Radar

Utility Scanning, or Soils GPR, is conducted similarly to two-dimensional Ground Penetrating Radar (GPR), but on a larger scale. During this process, a technician makes multiple passes over the ground surface using the GPR machine. This device has a transmitter located at the rear, which sends radio waves into the material beneath it. As these waves penetrate the ground, they interact with any embedded objects, causing some of the signals to reflect back. A receiver at the front of the machine captures these reflected signals and converts them into data for the GPR technician to analyze.

 

The technician interprets this data by examining hyperbolas displayed on the screen. This enables them to determine the presence of embedded items, their depth within the material, and the general width of each item. Using a cursor, the technician realigns the cart to the center of the identified items and marks their locations on the ground surface. Although certain information from the scan can aid in identifying these items, there is no definitive way to ascertain their exact identity using GPR alone. Therefore, items are marked based on the identifying characteristics of the observed hyperbolas. Items that appear out of place or differ from surrounding items are flagged as conflict items since their identities cannot be determined.

 

Soils GPR operates on a much larger scale, utilizing an antenna that differs from that used for concrete. The frequency used is much lower, allowing for better penetration in soil. This technology enables the technician to detect soil disturbances or embedded objects that may be up to 30 feet below the surface. The device's penetrating ability significantly depends on the density and moisture content of the soil being scanned. It is more effective at penetrating normal soils than clay.

 

Additionally, Soils GPR can locate embedded items that may be energized. With the LineTrac attachment, the system can detect the electromagnetic field generated by electrical circuits, making these items easier to locate.

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Soils GPR can also be completed for a three-dimensional. The technician will make passes every one to two feet of the scan area. Thees individual files are then uploaded into specific software to render a three-dimensional model of the area. Unfortunately, this process must be completed offsite, as the scanner cannot render a model this large.