Ground-penetrating radar (GPR) provides a high resolution, cross-sectional image of the shallow subsurface. This non-intrusive method uses a short pulse of electromagnetic energy that is radiated downward. When this pulse strikes an interface between layers of material with different electrical properties, part of the wave reflects back, and the remaining energy continues to the next interface. Depth measurements to interfaces are determined from travel time of the reflected pulse and the velocity of the radar signal.
Applications of GPR: