Ground penetrating radar (GPR) provides a graphic image of the subsurface and has a variety of applications from locating buried tanks or drums, to pipes and utilities, landfill cells, or geologic features such as ancient sinkholes and faults, as well as, sand and gravel deposits. GPR utilizes high frequency radio waves to probe the subsurface without disturbing the ground surface. GPR data is collected continuously as the instrument is towed over the ground surface. Radar pulses are transmitted downward from an antenna and are reflected back from underground surfaces. The reflected signals return to a receiving antenna creating a continuous graphic 2D profile of the subsurface. Reflecting surfaces appear as bands on the profile, while isolated objects often appears a arch-shaped or parabolic reflections. The results of a GPR survey are usually presented to the client in a full report which includes an index map showing locations of traverses with original data, interpreted radar anomalies, description of the methods, and the basis for interpretation of anomalies. GPR works particularly well in areas with relatively sandy soils, but is generally limited by shallow conductive soils such as clayey soils. GPR can generally achieve depths of investagation from a few feet to a hundred feet depending on soil types and the frequency of the antenna used for the survey.