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 →)

Acronym for electromagnetic radiation hazards.

A unit of plane angle measure equal to the angle subtended at the center of a circle by an arc equal in length to the radius of the circle.
Note: One radian is equal to 360°/2, which is approximately 57° 17'
4
4. 6".

Radiant power, in a given direction, per unit solid angle per unit of projected area of the source, as viewed from the given direction.
Note: Radiance is usually expressed in watts per steradian per square meter.

Radiant power emitted into a full sphere, i.e., 4 sr (steradians), by a unit area of a source, expressed in watts per square meter. Synonym radiant exitance.

Energy in the form of electromagnetic waves.
Note 1: Radiant energy may be calculated by integrating radiant power with respect to time.
Note 2: Radiant energy is usually expressed in joules.

Synonym radiant emittance.