Glossary:

ATIS Telecom Glossary

Search Keyword By: A

Select a term name to open its entry and any media references. Longer definitions end with a “Read More” link.

aperture distortion

In facsimile, the distortion of the recorded image caused by the shape and finite size of the scanning and recording apertures.
Note: The distortion may occur in one or more attributes of the recorded image, such as in resolution, density, or shape.

aperture illumination

1. The field distribution, in amplitude and phase, over the antenna physical aperture.
2. The phase and amplitude of the element feed voltages or the distribution of the currents in an array of elements.

aperture-to-medium coupling loss

The difference between the theoretical gain of a very large antenna, such as the antennas in beyond-the-horizon microwave links, and the gain that can be realized in operation.
Note 1: Aperture-to-medium coupling loss is related to the ratio of the scatter angle to the antenna beamwidth.
Note 2: The "very large antennas" are referred to in wavelengths; thus, this loss… (Read More →)

API

Applications Programming Interface

APNT

Alternative Positioning, Navigation, and Timing

APOD

ATIS Point of Deployment (a. k. a. , VueKey)

apogee

In an orbit of a satellite orbiting the Earth, the point that is farthest from the gravitational center of the Earth.

apparent power

In alternating-current power transmission and distribution, the product of the rms voltage and amperage.
Note 1: When the applied voltage and the current are in phase with one another, the apparent power is equal to the effective power, i.e., the real power delivered to or consumed by the load. If the current lags or leads the applied voltage, the apparent… (Read More →)

Showing 401–410 of 673 results