Sound Navigation and Ranging
SONAR, as it is most commonly known as has been around since the beginning of time. Animals have used this technique and survived because of it for millions of years. Among the most common are bats and dolphins.
http://www.animalport.com/img/Bats.jpg
http://www.aristov.com/photo/anim/sea/dolphin.jpg
But enough of the cute animals, lets talk about what Sonar is, and how we have utilized it.