Extracting tomographic images of interior structures of cylindrical objects and trees using Ground Penetrating Radar method

In this study, the Ground Penetrating Radar (GPR), which is a geophysical prospecting method for shallow-depth research, is applied on cylindrical objects in order to extract information about their internal structures. In the first step, two different models containing cavities and filling material are designed programmatically. These models are then used to compute theoretical radargram images using “gprMax” program, simulating electromagnetic (EM) waves’ propagation through modelled media. Next, the GPR method is applied on actual media created with cylindrical objects and artificially created cavities, replicating the designed models for the theoretical calculations. Additionally, a tree trunk with a hollow column on the central axis is prepared and subjected to GPR method measurements. The measurements are carried on using a circular measurement setup and resulted in the actual radargram images achieved from actual measurements. Finally, the actual radargrams are compared with the theoretical radargrams and converted into tomographic images by using “backprojection” method, ultimately providing clues about the internal structure of the studied media. The measurement setup and the proposed imaging method provided fast and successful results in investigating internal structures of cylindrical objects.