1. Acronym for radio detection and ranging.
1. A radio detection system that transmits short bursts (pulses) of rf energy and detects their echoes from objects (targets) such as aircraft or ships.
Note: The round-trip propagation time for the echo return may be used to determine the target's range (distance from the radar's antenna). If the transmitting antenna has a… (Read More →)

1. A transmitter-receiver associated with a fixed navigational mark which, when triggered by a radar, automatically returns a distinctive signal which can appear on the display of the triggering radar, providing range, bearing and identification information. [NTIA] [RR]
2. A receiver-transmitter combination which sends out a coded signal when triggered by the proper type of pulse, enabling determination of range… (Read More →)

The range that corresponds to the situation in which a radar transmitter is on and hence the receiver must be off, so that the radar transmitted signal does not saturate, i.e., does not blind, its own receiver.
Note: Radar blind ranges occur because there is a time interval between transmitted pulses that corresponds to the time required for a pulse… (Read More →)

The magnitude of the radial component of velocity of an object, i.e., a target, relative to a radar site, that cannot be measured by the radar unit.
Note: Radar blind speeds occur because of the relationship between the transmitted pulse repetition rate (PRR) and the received pulse-repetition rate. The Doppler pulse repetition rate is the difference between the transmitted and… (Read More →)

An expression of the extent to which an object, i.e., a target, reflects radar pulses, usually with respect to their point of origin.
Note: The radar cross section of an aircraft can vary by a factor of over 100, depending on the aspect angle of the aircraft to the radar transmitter. Radar reflection off the nose of the aircraft usually… (Read More →)

Intelligence derived from data collected by radar. [JP 1-02]

The time required for a radar pulse to travel 1 mile (~
1. 6 km) to an object, i.e., to a target; reflect; and return to the receiver.
Note: A radar statute mile is approximately
1
0. 8 s (microseconds); a radar nautical mile is approximately
1
2. 4 s. The time for any other radar unit distance is readily… (Read More →)

The volume of space that is occupied by a radar pulse and that is determined by the pulse duration and the horizontal and vertical beamwidths of the transmitting radar.
Note: The radar cannot distinguish between two separate objects that lie within the same resolution cell. The radar resolution cell depth (RCD) remains constant regardless of the distance from the transmitting… (Read More →)

1. The detailed waveform of a detected radar echo.
Note: Radar signatures may be used to identify or distinguish among objects, i.e., targets, such as aircraft, decoys, missiles with warheads, and chaff. [From Weik '89]
2. The detailed characteristics of a radar transmission.
Note: Radar signatures based upon emission analysis may be used to identify or distinguish among specific radar… (Read More →)

An equation that expresses the radar horizon range (RHR), given by where RHRs is the radar horizon range in statute miles, h is the antenna height in feet, and a is the object critical altitude, i.e., the target altitude in feet, below which the radar cannot illuminate the object.
Note: The RHR is also given by where RHRk is the… (Read More →)