Have you ever wondered how stealth planes achieve invisibility, how sunken ships are found, or how fishermen track schools of fish in vast expanses of ocean? Radar and sonar echolocation--a simple matter of sending, receiving, and processing signals. Weaving history with simple science, Mark Denny deftly reveals the world of radar and sonar to the curious reader, technology buff, and expert alike. He begins with an early history of the Chain...