Ground penetrating radar. Forensic officer searching for buried evidence using a ground penetrating radar (GPR). The GPR emits a continuous pulse of microwave electromagentic energy into the ground and detects the backscattered energy. A buried object, or disturbance in the soil will cause the radar waves to change velocity and the reflected energy forms an image on the GPR computer screen. GPR can be used to search for buried evidence. It can also be used by industry to detect hidden cables and pipes in walls and under ground.