These allow the non destructive or non invasive detection of the presence and position of objects in the sub-soil to a depth of several metres, using the phenomenon of the reflection of electromagnetic waves of particular frequencies.
The system consists in a control and data acquisition unit, and of one or two antennae and permits the acquisition, elaboration and interpretation of data and the restitution of bi-tri dimensional graphs (paper or electronic) in design or in section. According to the number of antennae and frequencies used for introspection, the technique permits the more or less accurate detection of the position and dimension of objects present in the sub-soil.
The use of the technology is preliminary to the use of no-dig techniques which involve reduced drilling or digging and, as well as being useful for the planning of technological networks, allow the execution of stratigraphical profile analysis, archeological, civil engineering and environmental surveys. Its utilization is mainly conditioned by the geological conditions of the soil (the presence of water, in fact,
diminishes the penetrative capacity of the electromagnetic waves) and the type of objects present in the sub-soil (for instance, the presence of metallic chain mail).