Ground penetrating radar systems, which can be used to sense the density of objects under the Earth, are normally seen as a fairly exotic piece of equipment. Naturally, such devices cost thousands of dollars. Mirel Paun’s “GPRino” prototype, though, aims to accomplish this viewing task for the comparatively paltry sum of $300.
The GPRino uses antipodal Vivaldi antennas to see into the ground, under control of an Arduino Mega. Onboard visualization is handled by an LCD shield, and collected data can also be transmitted to a PC for further analysis.
More information homemade GPR can be found in Paun’s project write-up. You can see a demo of it scanning in the first video below, while a quick clip of its wheel switch (a simple cam setup) is shown in the second.