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.
Main article: Fire-control radar |
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.
Main article: Missile guidance |
Instrumentation radars are used to test aircraft, missiles, rockets, and munitions on government and private test ranges. They provide Time, Space, Position, Information (TSPI) data both for real time and post processing analysis.[2]
Repurposed NASA and military radars
Commercial off-the-shelf (COTS)
Custom
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.[citation needed]
Weather radars can resemble search radars. This radar uses radio waves along with horizontal, dual (horizontal and vertical), or circular polarization. The frequency selection of weather radar is a performance compromise between precipitation reflectivity and attenuation due to atmospheric water vapor. Some weather radars uses doppler shift to measure wind speeds and dual-polarization for identification of types of precipitations.[3][4]
Mapping radars are used to scan a large region for remote sensing and geography applications. They generally use synthetic aperture radar, which limits them to relatively static targets, normally terrain.
Specific radar systems can sense a human behind walls. This is possible since the reflective characteristics of humans are generally more diverse than those of the materials typically used in construction. However, since humans reflect far less radar energy than metal does, these systems require sophisticated technology to isolate human targets and moreover to process any sort of detailed image. Through-the-wall radars can be made with Ultra Wideband impulse radar, micro-Doppler radar, and synthetic aperture radar (SAR).[5]
Radar range and wavelength can be adapted for different surveys of bird and insect migration and daily habits. They can have other uses too in the biological field.
Further information: Bioradiolocation |