3D Ground Penetrating Radar

Three-Dimensional Ground Penetrating Radar (GPR) is an advanced technique used for scanning concrete to locate embedded objects. During this process, a technician operates the GPR machine, making passes over the concrete surface every two inches. Similar to two-dimensional GPR, a transmitter located at the rear of the machine sends radio waves into the concrete. As these waves penetrate the material, they interact with any embedded objects, causing some signals to reflect back. A receiver at the front of the machine captures these reflected signals and converts them into data for analysis.

 

To present the findings, the technician interprets the data by examining hyperbolas displayed on the screen. This allows them to determine the presence of embedded objects, their depth within the concrete, and their general width. Using a cursor, the technician realigns the cart to the center of the identified objects and marks their locations on the concrete surface. While some information from the scan can help in identifying these objects, there is no definitive way to ascertain their exact identities using GPR alone. Instead, items are marked based on the identifying characteristics of the observed hyperbolas. Items that appear out of place or show different characteristics compared to nearby objects are indicated as conflict items since their identities cannot be determined.

 

What sets three-dimensional GPR apart is that the collected data is analyzed by a computer to create a three-dimensional model of the scanned area. Using this model, the technician can validate the embedded objects identified through two-dimensional GPR and locate any items that may have been overlooked. Three-dimensional GPR is particularly effective for detecting items near the bottom of the slab or those obscured by multiple targets found at the top of the slab, making them difficult to locate.