Distance measuring equipment

Distance measuring equipment, or DME, is a special tool that helps people measure how far away things are. It works kind of like a timer - when you start it, it sends out a signal called a "pulse" that travels through the air really fast. When the pulse hits something, like a plane or a mountain, it bounces back and the DME measures how long it takes for the pulse to come back.

This time measurement is then translated into the actual distance between the DME and the object it bounced off of. So if the DME sends out a pulse and it takes 1 second for the pulse to come back, then the object is about 1 mile away from the DME.

DME is really useful for pilots, because they can use it to figure out how far away they are from an airport, which helps them land safely. It can also help people on the ground measure distances between things like buildings or mountains. So, think of a DME like a magic tool that helps you figure out how far away things are!