It is an old trope in submarine movies. A sonar operator strains to hear things in the ocean but dares not “ping” for fear of giving away the boat’s location. Radar has a similar problem. If you want to find an airplane, for example, you typically send a signal out and wait for it to […]
The basic principle of radar systems is simple enough: send a radio signal out, and measure the time it takes for a reflection to return. Given the abundant sources of RF signals – television signals, radio stations, cellular carriers, even Wi-Fi – that surround most of us, it’s not even necessary to transmit your own […]