Radar warning system
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A radar warning system or a radar detector is an electronic device that can register the electromagnetic waves from radar systems and issues a warning or reacts to them in a different way.
In the simplest case, such a device consists of a suitable antenna with a downstream HF rectifier. This causes a demodulation of the radar impulses and delivers a signal of the impulse sequence which is within the audible range (the repetition frequency is approx. 100 to 1000 Hz depending on the range of the radar device).
However, a radar warning system often includes one or more antennas and a signaling / command system connected to the receiver .
Radar detector in road traffic
Radar detectors can be used in motor vehicles to warn of speed monitoring using continuous wave radar before the speed of the vehicle is recorded. There are also so-called radar jammers which try to interfere with the CW radar by sending radio waves.
Although it is legal to trade and own these devices in Germany, it has been prohibited to operate or carry them in the vehicle when they are ready for use since 2002. It constitutes an administrative offense, the discovery of which results in a fine of at least 75 euros and a point in the register of fitness to drive as well as the confiscation of the device. In the case law, purchase contracts for radar warning devices are classified as immoral and therefore void according to § 138 BGB, so that the buyer has to accept unusable devices. A new ruling by the Federal Court of Justice on November 25, 2009 no longer generally rules out the return despite immorality. Nevertheless, there is still legal uncertainty for buyers, as most court decisions deny the right of return.
In Austria and Switzerland, however, possession and therefore import from abroad is also prohibited. In Austria, on the other hand, devices that are integrated into navigation devices or smartphones and only display radar locations similar to the point of interest system are permitted .
A distinction must be made between radar systems as distance warning devices , which monitor both the distance and the speed difference to other vehicles and thus contribute to driving safety.
Radar detectors in the military
Radar detector (engl. Radar warning receiver or RWR ) are also used in combat aircraft and allow, depending on their complexity, a recognition of the generator of the radar radiation, the direction from which the radar radiation is and optionally the relative velocity to the transmitter, so to speak, to the electronic intelligence - ELINT . Based on the evaluated data, it is possible to infer an imminent attack, for example with rockets or FLAK, and automatic or manual countermeasures can be initiated (dropping of chaffs or decoys , attack by the radar station).
The first radar warning systems were used by the German Air Force on board night fighters from autumn 1943 , when it was discovered that British bombers were carrying radar systems. The Air Force developed the FuG 370 Naxos receiver , which could evaluate the radiation from the enemy radar transmitters in order to attack the bombers. Another device was the passive homing device FuG 227 for approaching the English "Monica" distance warning device . Similar devices (such as the Metox device) were then used by German submarines - over water - in order to be able to submerge in time before an impending air attack.
Other uses
Single-handed sailors traveling alone on a sailing boat use radar warning devices to be woken up in their sleep by radar signals from approaching ships.
Individual evidence
- ↑ Transparency in speed monitoring (PDF; 45 kB) General German Automobile Club. Retrieved on September 4, 2013. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ^ BGH judgment of February 23, 2005 . Hans Giese. Retrieved March 12, 2010.
- ↑ BGH judgment v. November 25, 2009 . Federal Court of Justice. Retrieved August 8, 2011.
- ↑ Most of the radar detectors are illegal! on ÖAMTC from January 28, 2010 accessed on June 15, 2011.
- ↑ Minutes of the meeting from September 2, 1943: First Naxos-Z installed in Ju 88. (PDF; 234 kB)
