Because you use light to communicate in sign language, and light is just an electromagnetic wave like radio but on another frequency. You just need to be in line of sight
Because you use light to communicate in sign language, and light is just an electromagnetic wave like radio but on another frequency. You just need to be in line of sight
RADAR: RA(dio) D(etection) A(nd) R(anging)
It doesn’t rely on self transmission. It can but you can detect and range other sources without generating it yourself.
That’s just what the acronym means, it doesn’t describes the actual process. I don’t think there is a single RADAR that doesn’t have a transmitter. At that point it would just be a… radio.
Passive radar?