While you might think of radar pointing toward the skies, applications for radar have found their way underground as well. Ground-penetrating radar (GPR) is a tool that sends signals into the earth ...

There is an associated Kickstarter crowd-fund. According to the Kickstarter page, the shield is known to be compatible with Uno, NerO, Leonardo and Mega 2560 Arduinos, and is though to be compatible ...

It's of course backwards compatible with existing Arduino add-ons, but sets itself apart with a new USB controller with lower latency and driver-free operation on Mac and Linux.