Electromagnetic Techniques
Fixed Frequency Electromagnetic (EM) Profiling
Outline
This is an active method that uses an electromagnetic (EM) signal to detect variations in subsurface conductivity. The EM signal is generated by a transmitter coil from where it radiates into the ground generating eddy currents within any subsurface conductors. These produce a secondary EM signal that is detected on surface by a receiver coil. The spacing between the coils determines the maximum depth of investigation in any given setting. Instruments commonly used in environmental and engineering applications are capable of site investigation to depths of between 1-30m. However, target resolution varies inversely with depth.
