“echo”的概念、定义、翻译、参考文献-科学参考

echo

Physics

The reflection of a wave by a surface or object so that a weaker version of it is detected shortly after the original. The delay between the two is an indication of the distance of the reflecting surface. An echo sounder is an apparatus for determining the depth of water under a ship. The ship sends out a sound wave and measures the time taken for the echo to return after reflection by the sea bottom. Sonar (sound navigation ranging) is a technique for locating underwater objects by a similar method. Echoes also occur with radio waves; reflection of waves causes an echo in radio transmission and ghosts in television pictures. See also radar.

Computer

1. The reflection of transmitted data back to its source (or, as a verb, to reflect transmitted data back to its source). For example, characters typed on the keyboard of a data terminal (connected to a computer) will not appear on the display of the terminal unless they are echoed. The echoing process may be done locally by the terminal itself, by a modem, by an intervening communication processor, or by the computer to which the terminal is attached.
2. A phenomenon in voice circuits (e.g. telephone circuits) that upsets the operation of modems. Most modems therefore incorporate echo suppression.

Electronics and Electrical Engineering

1. A communications wave that has been reflected or refracted and that has sufficient magnitude and delay to distinguish it from the direct wave. In radio an echo is heard. In television it appears as a ghost on the screen; it may or may not be heard simultaneously.
2. The portion of a transmitted radar signal reflected back to the receiver.

单词	echo
释义	echo Physics The reflection of a wave by a surface or object so that a weaker version of it is detected shortly after the original. The delay between the two is an indication of the distance of the reflecting surface. An echo sounder is an apparatus for determining the depth of water under a ship. The ship sends out a sound wave and measures the time taken for the echo to return after reflection by the sea bottom. Sonar (sound navigation ranging) is a technique for locating underwater objects by a similar method. Echoes also occur with radio waves; reflection of waves causes an echo in radio transmission and ghosts in television pictures. See also radar. Computer 1. The reflection of transmitted data back to its source (or, as a verb, to reflect transmitted data back to its source). For example, characters typed on the keyboard of a data terminal (connected to a computer) will not appear on the display of the terminal unless they are echoed. The echoing process may be done locally by the terminal itself, by a modem, by an intervening communication processor, or by the computer to which the terminal is attached. 2. A phenomenon in voice circuits (e.g. telephone circuits) that upsets the operation of modems. Most modems therefore incorporate echo suppression. Electronics and Electrical Engineering 1. A communications wave that has been reflected or refracted and that has sufficient magnitude and delay to distinguish it from the direct wave. In radio an echo is heard. In television it appears as a ghost on the screen; it may or may not be heard simultaneously. 2. The portion of a transmitted radar signal reflected back to the receiver.
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