New Looking Glass

摘要

Since Simon Lake developed the U.S. Navy's first periscope in 1902, there have been countless refinements, but one thing has remained unchanged: when a submarine wants to know what's on the surface it has to poke up a mast. On surveillance missions, that compromises its stealth, because the mast generates a radar return and creates a wake. And even on routine missions, coming shallow to use the periscope runs the risk of a sub surfacing under a ship it missed on sonar.