Time Domain Electromagnetic (TDEM) Surveys

High-Resolution Imaging of Deep Conductors: TDEM surveys employ pulsed electromagnetic waves transmitted via a surface loop to induce eddy currents in subsurface conductors (depths of 10–400+ meters). These currents generate secondary electromagnetic fields, measured by a receiver loop to map variations in conductivity and resistivity with exceptional depth penetration and resolution. Key advantages include adjustable depth investigation, with customizable loop sizes and pulse timings optimizing for shallow UXO detection (<30m) or deep mineral/water exploration (>300m); lithology-independent effectiveness in resistive bedrock where traditional methods fail; multi-application versatility from mineral exploration to environmental and engineering challenges; and no ground contact, with airborne or ground configurations minimizing site disturbance. Critical applications cover mineral exploration (massive sulfides, graphite, conductive ore bodies), groundwater mapping (saline/freshwater interfaces, aquifer geometry), geotechnical/environmental surveys (levee integrity, UXO detection, contaminant plumes), and infrastructure planning (void/cavity detection, bedrock profiling). The technical edge includes time-decay analysis differentiating highly conductive (e.g., metal) from moderately conductive (e.g., clays) targets, 3D inversion capability resolving complex subsurface geometries, and airborne hybrid systems (helicopter-towed) for rapid, large-area coverage. Precision depth profiling enables unmatched conductor detection.