Selection tool
Depth, resolution, cost — pick two
No method wins on every axis. Select up to four to compare, or read the scatter below: depth of investigation against resolution, with marker size showing relative cost.
| Attribute | GPR | TEM/TDEM | IP/ERT |
|---|---|---|---|
| Domain | Frequency domain | Time domain | Galvanic |
| Source | Impulse radar antenna | Switched transmitter loop | Injected DC / low-frequency current |
| Frequency band | 10 MHz - 2.6 GHz | Equivalent 1 Hz - 100 kHz | DC - 10 Hz |
| Depth range | 0.1 - 30 m | 20 - 1,500 m | 2 - 500 m |
| Resolution | Very high (centimetres) | Good for conductors | High near surface, degrades with depth |
| Typical cost | Low | Moderate | Low to moderate |
| Survey speed | Fast - walking or vehicle towed | Moderate - loop layout dominates | Slow - electrodes must be planted |
| Best terrain | Dry, resistive ground; concrete; ice; sand | Open ground; loops need clear space | Ground where electrodes can be coupled |
| Simulator | Open | Open | Open |