This is a great website, sensorsmag.com. I could spend days reading articles. There's a lot of Information on there, I had no idea. Jim Zweighaft probably knows about it because he teaches the sensor course, I had no idea. It's wonderful. So, there's a PDF of this. I think I put four PDFs out and D2L in addition to the slides for this week. So, when it says see PDF, you can go grab the PDF or you can follow that link and go read more. There's all kinds of stuff out there. At the sensorsmag and this particular article, categorized levels of autonomous vehicle driving. So, level zero, human controls everything so there's no automation. Level one, you've got assisted driving, cruise control, and adaptive cruise control. Level two, they're called partial automation. So, the driver must monitor the vehicle at all times. At least one system is fully automated, like lane control, lane centering, or cruise control, something along those lines. Level three is conditional automation. The driver monitors the vehicle at all times, and safety critical systems under certain conditions are shifted to the vehicle. Level four is high automation. No monitoring of the vehicle by the driver. However, not all driving scenarios are covered, for example, in climate weather or other scenarios like that [inaudible] covered. Then we've got the full automation at level five, operator free driving. They snapped this picture out of there so we could talk about it. So, there is an electronic control unit that's monitoring all these sensors. So, LIDAR is light distance and ranging, radars, radio distance and ranging, there's image sensors. These sensors are located all around the vehicle to create a 360 degree awareness of objects in relationship to the vehicle. There are some ultrasonic technologies in place, but they point out that radar is poised to replace all the ultrasonics.