GPR for road inspection: Georeferencing and efficient approach to data processing and visualization

GPR is a recommendable non-destructive technique for thickness measurement of pavement layers because data acquisition takes place at normal traffic speeds, making GPR a cost-effective technique. On the other hand, the large collected data, when the GPR system is mounted on a moving vehicle, is difficult to process. Given that processing is conducted by qualified practitioners, it is a key to obtain software tools that allow for accurate thickness measurements and fast processing times. In this paper, an easy to use and intuitive tool for pavement thickness measurement is presented. Exploiting the power of C++ programming language and the Qt framework advantages for developing applications with graphic interface, a simple and intuitive tool for a qualified worker is implemented in order to reduce the processing times and to give information at the earliest possible moment. Furthermore, the software provides a visualization application for the georeferencing of the field GPR data by using additional GPS (Global Positioning System) data. Given that the GPR acquisition software can connect to an external GPS for trace tagging, NMEA synchronization was used in this case. If the connection is set properly, the GPR acquisition software creates a number of files in order to get the GPR traces paired with a GGA sentence. After post-processing, all the traces are referenced to a SBET (Smooth Best Estimated Trajectory).