| Webster's Online Dictionary |
| Expressions | Domain | Definition | |
| Angular beam width | Environment | In radar, the angle subtended in the horizontal plane by the radar beam. (references) | |
| Beam width | Aerospace | A measure of the concentration of power of a directional antenna. It is the angle in degrees subtended at the antenna by arbitrary power-level points across the axis of the beam. This power level is usually the point where the power density is one-half that which is present in the axis of the beam at the same distance from the antenna (half-power points). Also called beam angle. The beam width of a radar determines the minimum angular separation which two targets can have and still be resolved. Roughly speaking, two targets at the same range whose angular separations at the radar antenna exceeds one-half of the beam width between half-power points will be resolved or distinguishable as two individual targets. The smaller the beam width, the greater the annular resolving power. Beam width may be at different locations through the axis depending upon the shape of the antenna reflector. (references) | |
| Beam width | Military | (DOD) The angle between the directions, on either side of the axis, at which the intensity of the radio frequency field drops to one-half the value it has on the axis. (references) | |
| Beam width | Space | The angle, measured in a horizontal plane, between the directions at which the intensity of an electromagnetic beam, such as radar or radio beam, is one-half its maximum value. For SAR applications, both the vertical beam width (affecting the width of the illuminated swath) and the horizontal or azimuth pattern (which determines, indirectly, the azimuth resolution) are frequently used concepts. Beam width may be measured in the one-way or two-way form, and in either voltage or power. (references) | |
| Beam width | Weather | The angular width of the radar beam. (references) | |
| Half Power Beam Width | Weather | The HPBW is the angular width between the two directions of the microwave radiometer antenna at which the main beam gain function is one-half its maximum value within a plane containing the maximum gain of the main beam lobe. The HPBW may also be the physical size of the projection of that angle at the location where the measurement is taken. (HPBW). (references) | |
Source: compiled by the editor from various references; see credits. | Top | ||
