Contraction for pilot balloon observation.

Video Display Terminal. An input and display device which includes a keyboard and a screen and allows a human to communicate with a computer.

Transistor-Transistor Logic.

An instrument for measuring the pressure of the atmosphere. The two principle types are aneroid and mercurial.

February 2nd. In American folklore, a day that is popularly supposed to provide the key to the weather for the remainder of the winter. Specifically, if the ground-hog upon emerging from its hole casts a shadow, it will return underground, thereby forebod ...

Any one of numerous devices for the measurement of either speed alone or of both direction and speed (set and drift) in flowing water.