Radar is a useful tool with familiar uses such as detecting aircraft and observing weather. It also has some less known applications, such as a technology known as ground-penetrating radar (GPR).

One of the most interesting is [Glenn Powers]’ Open Ground Penetrating Radar. It’s exactly what the title says: an open-source radar system that can see into the Earth for less than $500.

Ground penetrating radar detects electrical discontinuities in the shallow subsurface (<50m) by generating pulses of high-frequency electromagnetic energy and detecting the reflections from the ...