Радар түрлері мен сипаттамалары

Specific radar designs and specifications
This is a list of different types of radar.

Search radars scan great volumes of space with pulses of short radio waves. They typically scan the volume two to four times a minute. The waves are usually less than a meter long. Ships and planes are metal, and reflect radio waves. The radar measures the distance to the reflector by measuring the time of the roundtrip from emission of a pulse to reception, dividing this by two, and then multiplying by the speed of light. To be accepted, the received pulse has to lie within a period of time called the range gate. The radar determines the direction because the short radio waves behave like a search light when emitted from the reflector of the radar set's antenna.

Targeting radars utilize the same principle but scan smaller volumes of space far more often, usually several times a second or more, while a search radar will scan a larger volume less frequently. Missile lock on describes the scenario where a targeting radar has acquired a target, and the fire control can calculate a path for the missile to the target; in semi active radar homing systems, this implies that the missile can "see" the target that the targeting radar is "illuminating". Some targeting radars have a range gate that can track a target, to eliminate clutter and electronic countermeasures.

Radar proximity fuzes are attached to anti aircraft artillery shells or other explosive devices, and detonate the device when it approaches a large object. They use a small rapidly pulsing omnidirectional radar, usually with a powerful battery that has a long storage life, and a very short operational life. The fuzes used in anti aircraft artillery have to be mechanically designed to accept fifty thousand g, yet still be cheap enough to throw away.

Navigational radars resemble search radar, but use very short waves that reflect from earth and stone. They are common on commercial ships and long distance commercial aircraft. Marine radars are used by ships for collision avoidance and navigation purposes. The frequency band of radar used on most ships is X band (9 GHz/3 cm), but S band (3 GHz/10 cm) radar is also installed on most oceangoing ships to provide better detection of ships in rough sea and heavy rain condition. Vessel traffic services also use marine radars (X or S band) for tracking ARPA and provides collision avoidance or traffic regulation of ships in the surveillance area. General purpose radars are increasingly being substituted for pure navigational radars. These generally use navigational radar frequencies, but modulate the pulse so the receiver can determine the type of surface of the reflector. The best general purpose radars distinguish the rain of heavy storms, as well as land and vehicles. Some can superimpose sonar and map data from GPS position.