Top Down Image News Today

Debris site if the pinger cant find it. this emits sound. >> reporter: like hydrophones, sonars work better in very deep water. but coleman says in shallow water, the search can move along more quickly. sonar is just showing us whats at the bottom, right? >> exactly. its emitting that sound. as the sound comes back off the bottom, its interpreting it to draw a 3-d image of whats on the sea floor. and it also generates a top-down image. >> reporter: that imagine will help investigators mark the d...