- Industry: Telecommunications
- Number of terms: 29235
- Number of blossaries: 0
- Company Profile:
ATIS is the leading technical planning and standards development organization committed to the rapid development of global, market-driven standards for the information, entertainment and communications industry.
Radio reception in which a resultant signal is obtained by combining or selecting signals, from two or more independent sources, that have been modulated with identical information-bearing signals, but which may vary in their fading characteristics at any given instant. Note 1: Diversity reception is used to minimize the effects of fading. Note 2: The amount of received signal improvement when using diversity reception is directly dependent on the independence of the fading characteristics.
Industry:Telecommunications
Radio wave propagation in which the direction of the incident and scattered waves, resolved along a reference direction (usually horizontal) are oppositely directed. A signal received by backscattering is often referred to as "backscatter. " 2. In optics, the scattering of light into a direction generally opposite to the original one.
Industry:Telecommunications
Radiodetermination used for purposes other than those of radionavigation.
Industry:Telecommunications
Radiodetermination using the reception of radio waves for the purpose of determining the direction of a station or object.
Industry:Telecommunications
Radiolocation intended for the determination of position or direction or for obstruction warning in navigation. 2. Radiodetermination used for the purposes of navigation, including obstruction warning.
Industry:Telecommunications
Radionavigation equipment, on board an aircraft or spacecraft, used to determine the height of the aircraft or the spacecraft above the Earth's surface or another surface.
Industry:Telecommunications
Random noise that originates outside the Earth's atmosphere. Note: Cosmic noise characteristics are similar to those of thermal noise. Cosmic noise is experienced at frequencies above about 15 MHz when highly directional antennas are pointed toward the Sun or to certain other regions of the sky such as the center of the Milky Way Galaxy. Synonym galactic radio noise.
Industry:Telecommunications
Rapid variation of signal parameters, such as amplitude, phase, and frequency. Note: Examples of flutter are (a) rapid variations in received signal levels, such as variations that may be caused by atmospheric disturbances, antenna movements in a high wind, or interaction with other signals, (b) in radio propagation, a phenomenon in which nearly all radio signals that are usually reflected by ionospheric layers in or above the E-region experience partial or complete absorption, (c) in radio transmission, rapidly changing signal levels, together with variable multipath time delays, caused by reflection and possible partial absorption of the signal by aircraft flying through the radio beam or common scatter volume, (d) the variation in the transmission characteristics of a loaded telephone circuit caused by the action of telegraph direct currents on the loading coils, (e) in recording and reproducing equipment, the deviation of frequency caused by irregular mechanical motion, e.g., that of capstan angular velocity in a tape transport mechanism, during operation. Synonym frequency flutter.
Industry:Telecommunications
Rapid variation of signal parameters, such as amplitude, phase, and frequency. Note: Examples of flutter are (a) rapid variations in received signal levels, such as variations that may be caused by atmospheric disturbances, antenna movements in a high wind, or interaction with other signals, (b) in radio propagation, a phenomenon in which nearly all radio signals that are usually reflected by ionospheric layers in or above the E-region experience partial or complete absorption, (c) in radio transmission, rapidly changing signal levels, together with variable multipath time delays, caused by reflection and possible partial absorption of the signal by aircraft flying through the radio beam or common scatter volume, (d) the variation in the transmission characteristics of a loaded telephone circuit caused by the action of telegraph direct currents on the loading coils, (e) in recording and reproducing equipment, the deviation of frequency caused by irregular mechanical motion, e.g., that of capstan angular velocity in a tape transport mechanism, during operation. Synonym frequency flutter.
Industry:Telecommunications
Rapid, repeated phase perturbations that result in the intermittent shortening or lengthening of signal elements. Note 1: Phase jitter may be random or cyclic. Note 2: The phase departure in phase jitter usually is smaller, but more rapid, than that of phase perturbation. Phase jitter may be expressed in degrees, radians, or seconds. Phase jitter is usually random. However, if cyclic, phase jitter may be expressed in hertz as well as in degrees, radians, or seconds.
Industry:Telecommunications
