Autonomous and semi-autonomous driving systems are already getting pretty good under favorable driving conditions, but one of most people’s main concern is about how a self-driving car would handle heavy rain or snow. While Tesla’s Autopilot is equipped with a sensor suite consisting of cameras, a radar and sonars, Ford’s self-driving car prototype is powered by a lidar system, not unlike Google’s prototypes. Cameras are getting better every year and computer vision technology is improving at an impressing rate, but lidars, although more expensive and heavier on the data (Ford says its car can collect and process more data in an hour than the average person uses in mobile-phone data in 10 years), are especially precise.