Acronym for sound navigation and ranging. A device that is used primarily for the detection and location of underwater objects by reflecting acoustic waves from them, or by the interception of acoustic waves from an underwater, surface, or above-surface acoustic source.
Note: Sonar operates with acoustic waves in the same way that radar and radio direction-finding equipment operate with electromagnetic… (Read More →)

Acronym for synchronous optical network. An interface standard for synchronous optical-fiber transmission, applicable to the Physical Layer of the OSI Reference Model.
Note: SONET uses a basic bit rate of
5
1. 840 Mb/s, called OC-1 (optical carrier 1). The SONET hierarchy consists of preset integral multiples of OC-1, i.e., OC-3, OC-12, OC-48, etc. [T
1. X1]

In sonar systems, a device (a) that is used to detect acoustic waves, such as those produced by ships and submarines, (b) that, when activated, relays information by radio, (c) that may be active or passive, and (d) that may be directional or nondirectional. [From Weik '89]

See sonar.

See acoustic wave.

A telephone in which the operating power is derived from the speech input only.

A station equipped with an ionosphere sounder for realtime monitoring of upper atmosphere phenomena or to obtain data for the prediction of propagation conditions. [NTIA]

In automated HF radio systems, the broadcasting of a very brief signal, containing the station address, station identifier, or call sign, to permit receiving stations to measure link quality.

In communications, that part of a system from which messages are considered to originate.

In optical systems, the ratio of emitted optical power of a source to the input electrical power.