Ultrasound performs well in most situations, since it is not affected by the majority of weather conditions. Although ultrasonic sensors provide relatively little detail, they are not dependent on light, which can be an advantage in cases where not enough or too much light could yield misleading results. They also work in rain, fog, and snow, as long as the sensor itself is not covered by dirt, snow, or ice. In indoor, city, or crowded environments, their ability to detect non-metallic materials offers an additional safety measure in regard to pedestrians.
