A downward-facing penetrating radar, combined with sonar and magnetic imagers, allows you to detect (but not identify) minerals buried deep under the surface. Requires a huge amount of electricity.
A ground-penetrating scanner detects and illuminates underground deposits of resources (when selected), either jade, metal or chemfuel. Extracting materials from these deposits requires a deep drill. Only one scanner is needed to locate all deposits on the map. The scanner must be researched before it becomes available. It must be connected to power to function. A scanner is one of the most power-hungry devices. It can be turned off when not needed, to conserve power.