radar detector
A radar warning system or a radar detector is an electronic device that can register the electromagnetic waves of radar equipment and emits a warning against or otherwise respond.
In the simplest case, such a device from an appropriate RF antenna having a downstream rectifier. This causes a demodulation of radar pulses and provides an objective in the audible range of the signal pulse sequence ( repetition frequency, depending on the range of the radar at about 100 to 1000 Hz ).
Often, however, a radar warning system includes one or more antennas and a device connected to the receiver Melde-/Kommandoanlage.
Radar detectors on the road
Radar detectors may also be used in vehicles to warn of speed controls by means of continuous wave radar, even before the vehicle's speed is detected. There are also so-called radar jammer, the by transmitting radio waves attempt to interfere with the CW radar.
In Germany, although the actions and owning these devices instituting or ready-to use is legal, but banned in the vehicle since 2002. It is a legal offense, attracting the detection of at least 75 Euro fine and four points on their driving as well as the confiscation of the device by itself. The case law of contracts of sale of radar detectors are therefore classified as immoral and according to § 138 BGB to be void, so that buyers have to accept their waste equipment. A new judgment of the Supreme Court of 25 November 2009 includes the return, despite moral standards no longer in general. Nevertheless, there remains a buyer of legal uncertainty, since in most judicial decisions, the right of return is negative.
In Austria and Switzerland, however, the possession and therefore the import from abroad is prohibited. Are permitted in Austria, however, those devices that are integrated into navigation devices or smartphones and only a display of radar sites similar to the system of Points of Interest.
To be distinguished from such devices is radar distance warning as to oversee both the distance and the speed difference to other vehicles and thus contribute to driving safety.
Radar detectors in the military
Radar detector be used in the combat aircraft and allow, depending on the complexity of a detection of the generator of the radar radiation, the direction from which is the radar beam and, optionally, the relative speed of the transmitter. One speaks of Electronic Enlightenment - ELINT. According to the analyzed data can be concluded that an impending attack, for example, with rockets or flak and it can automatic or manual actions are initiated ( dropping chaff or decoys, attack the radar site ).
Radar warning systems date back to German developments in the 2nd World War, when it was realized that British bombers radar equipment brought with them. We developed the recipient FuG 370 Naxos, who could evaluate this radiation, in his turn to attack the bombers. Another device was the passive homing device FuG 227 for approach to English "Monica" distance warning device. Similar devices were used by German submarines to dive in time.
Other applications
Solo sailors who are alone on a sailboat on the go, use radar detectors to be woken up in my sleep by radar signals approaching ships.