LIDARs use a pulse of light to measure distance, usually from the time of flight to reflection and back. With a collection of these measurements they can determine their surroundings in two or three dimensions. LIDARs are used as one of the sensor systems for self-driving cars, in addition to cameras and other radar systems.
Robotic cars are still in the testing phase, but at some point in the future we can expect a busy intersection filled with them, trying to navigate their way through it. With multiple scanners per car, and possibly multiple beams per scanner, interfering signal sources could go over a hundred even in smaller stages.
When time of flight is used to measure the distance to the reflection, the interfering signals would produce multiple "distances", and it would most likely require multiple scans of the same point to average some kind of a reliable value from all the noise.
How do LIDAR systems differentiate their own signals from other sources? With the example of robotic cars, could this interference lead to an error state where traffic could gridlock from lack of valid data? Or is this even a problem?