A small anemometer with flat vanes which indicates the number of linear feet or meters of air which have passed the instrument during its exposure.

See captive balloon, ceiling balloon, constant-level balloon, free balloon, hurricane beacon, kytoon, Moby Dick balloon, pilot balloon, radiosonde balloon, rockoon, skyhook balloon, transosonde.

Physical equipment used in data processing. Compare to firmware, software.

Automated Weather Observing Station. A self-contained weather station designed to make aviation weather observations without operator involvement.

Rate of wind movement in distance per unit time.

A liquid-in-metal thermometer in which mercury is enclosed in a steel envelope. The change in internal pressure caused by the temperature variation is measured by a Bourdon tube which is connected to the mercury by a capillary tube. This instrument is hig ...