1. Pertaining to the delay introduced, by automated data processing, between the occurrence of an event and the use of the processed data, e.g., for display or feedback and control purposes.
Note 1: For example, a near-real-time display depicts an event or situation as it existed at the current time less the processing time.
Note 2: The distinction between near… (Read More →)

Synonym near-field region.

Crosstalk that is propagated in a disturbed channel in the direction opposite to the direction of propagation of a signal in the disturbing channel.
Note: The terminals of the disturbed channel, at which the near-end crosstalk is present, and the energized terminal of the disturbing channel, are usually near each other.

The diffraction pattern of an electromagnetic wave, which pattern is observed close to a source or aperture, as distinguished from a far-field diffraction pattern.
Note: The pattern in the output plane is called the near-field radiation pattern. Synonym Fresnel diffraction pattern.

1. The close-in region of an antenna wherein the angular field distribution is dependent upon distance from the antenna. Synonyms near field, near zone.
2. In optical fiber communications, the region close to a source or aperture.
Note: The diffraction pattern in this region typically differs significantly from that observed at infinity and varies with distance from the source.

A technique for measuring the refractive-index profile of an optical fiber by using an extended source to illuminate an endface and measuring the point-by-point radiance at the exit face.

In radio propagation, a wave that is reflected from the ionosphere at a nearly vertical angle and that is used in short-range communications to reduce the area of the skip zone and thereby improve reception beyond the limits of the ground wave.

Abbreviation for National Electric Code®.

1. For a given class of emission, the width of the frequency band which is just sufficient to ensure the transmission of information at the rate and with the quality required under specified conditions. [NTIA] [RR]
Note: Emissions useful for the adequate functioning of the receiving equipment, e.g., the emission corresponding to the carrier of reduced carrier systems, must be… (Read More →)

1. The legitimate requirement of a person or organization to know, access, or possess sensitive or classified information that is critical to the performance of an authorized, assigned mission.
2. The necessity for access to, or knowledge or possession of, specific information required to carry out official duties. [INFOSEC-99] See also Least Privilege.