Early warning is a marketing tool. There is no early warning. Most radar detectors just detect the signal.

hahahhahahahaha

receiver

A cobra detector is a radar detector. Radar detectors work the same way a radio receiver does. The radar detector looks for frequencies that a radar gun uses.

You need both a radar antenna and a GPS radar if this is marine then the radar antenna will perhaps include a Receiver and Transmitter as well and the GPS maybe a mushroom shape