The system measures the distance that each beam travels so that the car's computer can create a constantly updated three-dimensional map of the car's surroundings.

Between hutches, the beam travels in a transport tube.

When curved mirrors are used in a nearly confocal configuration, the beam travels on a circular zigzag path.

As the beam travels through the atmosphere, tiny fractions of the light are scattered by aerosols.

The fixed path beam travels a known and constant distance, whereas the variable path beam has its path length changed via rotating mirrors or other path changing mechanisms.