Electromagnetic Techniques
Ground Penetrating Radar (GPR) Profiling
Outline
This is an active method that uses a towed antenna to pulse microwave electromagnetic energy into the subsurface. As the polarised pulse travels downwards it interacts with materials within the ground and part of the energy is reflected back to the antenna at surface. The GPR unit measures the amplitude of the reflected signal and the time delay between the transmitted and received pulses in order to map subsurface features. The frequency of the antenna can be changed depending on the required depth of investigation and the nature of the expected target. Whilst the method is highly versatile it is not suitable for use over highly conductive ground.
