States of Practice and Research on Applying GPR Technology for Labeling and Scanning Constructed Facilities

Ground Penetration Radar (GPR) is now a mature technology with various applications for scanning different types of constructed facilities including underground utilities and structural systems. Several models of GPR scanners are commercially available and selecting the optimum machine for certain applications is a significant decision-making task for practitioners and researchers. As a result, there is a demand for reviewing the latest states of practice and research on applying GPR technologies to assist practitioners and researchers with their scanning tasks. This paper is an attempt to address the aforementioned issue through conducting an in-depth review on existing models of GPR scanners as well as a comprehensive review on undergoing research activities in this area. The results of this study are summarized in five sections: The first section provides a brief overview on the general structure of a GPR scanning system. The second section reviews the commercially available GPR machines plus the advantages, limitations, and specific application of each model. The latest state of research for scanning and labeling constructed facilities using GPR scanners is presented in the third section. The next section briefly reviews the postprocessing steps required to convert the raw data obtained from GPR scanners into rich information about the desired objects. Finally, the results of a comparative study conducted by the authors to evaluate the performance of two popular models of GPR scanners (StructureScan Mini XT and Handy Search NJJ-105) in scanning a number of structural elements (concrete walls, columns, and slabs) as case studies are presented.