LIDAR
From Memory Alpha, the free Star Trek reference
LIDAR (LIght Detection And Ranging) is a technology similar to RADAR (RAdio Detection And Ranging), but instead of using radio waves, LIDAR uses laser pulses to calculate how big and how far an object is. LIDAR was used in pre-warp civilizations, including those on Earth. The Ares IV, which was used in the early Mars missions, had LIDAR when it was engulfed in a subspace anomaly. (VOY: "One Small Step")
