Ground Penetrating Radar (GPR) is one of radar types that is often used to determine conditions inside or below some surface. GPR is also commonly used as a material evaluation tool by its trait as a non-destructive testing (NDT). One of the most important sections of GPR is signal processing system or GPR data processing that will filter all of the GPR survey results. Reflection signals gained by the radar antenna are then filtered to discover any objects located below the ground surface. The better the process in filtering data, the more accurate the GPR interprets the gained signal. This study aims to design a GPR data processing system that is sufficiently be able to interpret the gained signal so that it can accurately discover any objects located on the ground. This GPR data processing system is expected to work on a variety of frequencies and the application can be developed in various types. The aims of this study are designing and modifying the GPR data processing system.