As radars sensors are called that for a radar methods give either imaged or non-imaged information about remote from the location of the radar objects. Radar devices are also classified according to their main purpose.
Almost all radar devices that are primarily used to collect weather data are referred to as weather radar. Weather radars are divided into precipitation radars , wind profilers, and cloud profiling radars .
Coastal protection radar
Radar devices that are used as coastal protection radar are primarily intended to locate ships and boats on the water.
Compared to an air defense radar, they must have some special features. They use antennas with an inverted Cosecans² diagram in order to achieve the most uniform possible illumination of the water surface and to reduce unwanted echoes from aircraft.
In addition to the predominantly military use in the past, coastal protection radar devices are now used more to detect the boats of smugglers and illegal immigrants, for example in the Mediterranean region and on the Canary Islands.
Navigational radar devices are used for aircraft as well as for ships and boats, and they mostly work in the K u band or K a band . Imaging radar devices are implemented as pulse radar or continuous wave radar , which enable a panoramic operation (or only a sector section thereof). The display usually takes place in "Skin Paint Mode". Due to the different requirements for data acquisition, different antenna diagrams are used: Fan diagram for airborne navigation radars or also inverted Cosecans² diagrams in seafaring.
The Doppler frequency is no longer used in the navigation radar to detect moving targets , since the radar's own movement is superimposed on the received echo signal. The Doppler frequency is used in airborne devices to improve angular resolution . Most of the navigation radars used in shipping do not evaluate the Doppler frequency, however, since fixed targets such as coastlines also receive a Doppler frequency due to the ship's or boat's own movement. The echo signal of the sea waves (sea clutter ) is only suppressed by the radar signal processing due to the lower amplitude with the aid of threshold value circuits in the display.
Navigation radars for smaller boats and yachts are also designed as FMCW radars . These devices use a much lower power (in the range of 100 mW) than pulse radar devices with mostly a magnetron as a self-excited high-frequency generator (around 4 kW). In addition to the safety for the crew, the significantly reduced power consumption should also be mentioned as an advantage.
Ground penetrating radars
Special radar devices that work with different radar technologies are used to map or investigate soils or the upper soil layers of the earth's crust . Such devices are used both in geodesy and in the military .
Air traffic control radars
Air traffic control radars are used by air traffic controllers to ensure the safety of air traffic. Frequent applications of air traffic control radar devices (in A ir T raffic M anagement "ATM") are for example:
"En Route" radars
"En Route" (airway) radars work up to a range of around 450 km. They monitor air traffic outside of the special aerodrome areas.
Airport Surveillance Radar (ASR)
These airport surveillance radars are used by air traffic controllers for air surveillance. It helps them to keep track of all flight movements around the airfield and to ensure the ever-growing air traffic in a safe, orderly, and fast way. Usually the ASR work in the E-band up to a range of 60 nautical miles (approx. 120 km).
Precision Approach and Precision Landing Radar Systems (PAR)
The precision approach radar guides the aircraft approaching the airport safely to landing, even under poor visibility conditions . The radar device detects and accompanies aircraft during the final approach and landing phase. The deviations from the ideal approach line are transmitted to the pilot by radio.
Airfield surveillance radars
In fog or poor visibility show airfield surveillance radars (ger .: S urface M ovement R adar "SMR") of the tower crew to the entire airfield on a screen. With extremely short transmission pulses in the nanosecond range and a very high transmission frequency ( J to X band ), these radar devices can measure even the shortest distances with a very high resolution.
Newer devices use the frequency range above 90 GHz and monitor a distance of a few hundred meters. The entire radar device with a highly effective patch antenna fits into a radome the size of a rotating beacon . A large number of these radar devices are distributed on the airfield and feed their radar information into a network.
The availability of radar devices in the 94 GHz range makes it possible to use radar devices for automated control of the runways for foreign objects (protection from FOD ) during flight operations. Despite the rotating parabolic antenna, these radar devices are not much larger than a rotating beacon and can be used in large numbers on airfields along taxiways . At the same time, they monitor the airfield and report vehicle and passenger movements.
Air defense radars
Air defense radar devices locate flight targets at a great distance and measure their position, course and speed. The maximum range of air defense radar devices can therefore be 450 km (and often more!) With a full 360 ° all-round view.
Air defense radars are used in early warning systems to locate approaching enemy aircraft and missiles at a great distance. Because only a timely alert to the air defense can successfully ward off an attack.
So-called low -flying detection radar (GAP fillers) are used in difficult terrain, in which, for example, a radar all-round view is not possible due to deep mountain valleys . These are smaller, mostly very mobile radar devices with a small to medium range that feed their radar data into a network and thus enable a complete radar image in cooperation with long-range radar devices. One such low- flying detection radar for air surveillance is the RAC 3D "Flamingo", which is used in the Austrian armed forces.
For reconnaissance of the battlefield and for its own air defense, the army uses specialized radar devices with mostly lower transmission power.
Small mobile radar devices monitor the battlefield and give the operator an overview of the enemy's movements even in the dark and with poor visibility, such as B. the battlefield, maritime and coastal surveillance radar BOR-A 550 or the low-level aircraft reconnaissance radar DR-151 .
Weapon control radar
|Missile guidance radar
With the help of these radar systems, guns and rockets are aligned and guided towards the air target. Examples of weapon guidance radar are:
- Target display of the screen background as a colored area (details in the relevant entry at radartutorial.eu ( memento of the original from September 24, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and not yet checked. Please check the original and archive link according to instructions and then remove this notice. )
- C. Wolff, Radar Tutorial Precision Approach Radar