Traditional radar emits an elctromagnetic pulses in the radio wavelength, and measures the reflections generated when the pulses collide with objects. RF drone detection systems like Dedrone and AeroScope are passive systems, detecting the radio waves emitted from the object they are tracking. Since drones are often made from plastic materials which do not reflect radar waves very well, this is often more accurate than traditional methods, and reduces false positives from objects such as birds.