The ultrasonic sensor demonstrated displays a common quirk in bats. Through using sound waves, the ultrasonic sensor acts like a sort of ruler, measuring the distance between the object and the sensor. These sensors (at a much larger scale) are used in Alpha Wolf to calculate the distance between the drone and the ground. Ultrasonic range sensors also help provide a better description of the terrain. By inputting multiple of these sensors, we record the distance between the ground and the drone. If we notice a variation in these distances, we can deduce that the terrain is at a higher or lower elevation than the rest.