Moving in a circle at a constant speed means there is indeed an acceleration.If we have an object moving in a circle, the acceleration is pointed towards the center of the circle and depends on two things: the angular velocity (ω) and the circular radius (r).

But you can only measure where something’s going, and how fast, if you manage to hit it again and again.Blackmore's lidar reads the velocity of the objects it detects: The things moving away from the vehicle are in red, those moving toward it are in blue.