In order to acquire images of different sub-surfaces, IES use the ground penetrating radar technology. This nondestructive method uses electromagnetic radiation in the microwave band (UHF/VHF frequencies) of the radio spectrum, and detects the reflected signals from subsurface structures. GPR can be used in a variety media, including rock, soil, ice, fresh water, pavements and structures. It can detect objects, changes in material, and voids and cracks.
The depth range of GPR is limited by the electrical conductivity of the ground, the transmitted center frequency and the radiated power. For the research purposes IES uses antenas operable in a range from 300 to 900 MHz.