Two types of electronic countermeasures equipment were carried by the Defiant, both countering the German "Freya" early warning radar. The first system to be deployed was "Moonshine", which re-transmitted the radar's signals to simulate large formations of aircraft. As each "Moonshine" transmitter only covered part of the Freya's frequency, a formation of eight Defiants was needed, giving the appearance of over 100 aircraft. As the system required formation flying, it could only be used in daylight, where it could draw German fighters onto British fighters leaving another area relatively free for a British bombing raid.