Underground Imaging Sensors: What Do Magnetic, Thermal, Lidar and Radar Do?

Most underground imaging devices combine the data of several sensors rather than relying on one. Each sensor measures a different physical effect, so each has different strengths and weaknesses. In the Proton Elic series, the number and variety of sensors grows with the model.

Magnetic sensor

The Earth's magnetic field is not uniform; objects containing iron and some structures change it locally. A magnetic sensor measures these changes. Soil mineral content can also affect the field, so results should be interpreted carefully.

Thermal sensor

A thermal sensor images surface temperature differences. A void or moisture difference underground can show up in surface temperature. Weather, time of day and shade can change the result.

Lidar

Lidar measures distance with a laser beam and maps surface shape. It measures the terrain surface, not the soil beneath it, so it is used together with other sensors.

Radar

Radar sends electromagnetic waves and measures the returning reflection. Soil moisture and clay content can limit how far the waves travel. The Doppler method measures the frequency change caused by motion.

Why more than one sensor?

A single sensor may not be sufficient in every soil. Comparing the data of several sensors gives a more reliable assessment, but results still depend on the ground, moisture and user experience; no device can promise a 100% result.

Buying a device does not grant search or excavation permission. You must obtain the required permits from the competent authorities.