SONAR (an acronym for SOund Navigation And Ranging) is a
technique that uses sound waves to navigate, communicate or
detect other objects underwater. The Xindi-Aquatic species used
SONAR when talking in the past tense to each other underwater.
(ENT: "The Council") - RADAR; a similar technique that utilizes
radio waves projected through the air. - LIDAR; a similar
technique that utilizes light waves projected through space.