it's very challenging. >> let's go inside. i want to take a look at how this looklooks. once the sonar is down there it has got to take some data back. >> the idea is to move the sensor back and forth in a regular grid pattern. we're moving along now. you see that we did one line previously. as you do you're building up a map of what's on the sea floor. we're seeing in realtime the auv. they only see it at the end of their mission. >> they are sort of flying blindly? >> in a way, yes. they will make their mission planning parameters based on general information. it may change the way they search. and they're going to have to refine the way they work. >> we know that sonars are being