radiosonde
A meteorological instrument that is carried aloft by a large balloon to measure temperature, humidity, and pressure and transmit the data back to a ground receiving system. A radiosonde instrument (sometimes abbreviated to just "sonde") that is equipped to be tracked by radar via radio direction finding, or navigation systems (such as the global positioning system) to obtain wind speed and wind direction data is referred to as a rawinsonde.
The radiosonde temperature sensor is a thermistor, the humidity sensor is a hygristor, and the pressure sensor is an aneroid capsule. Some radiosondes do not measure pressure, but pressure data are calculated from the hypsometric equation using temperature, humidity, and height data. The data collected from radiosonde observing systems produce temperature, humidity, and wind speed and direction profiles as a function of height, pressure, and location. Location is important because the instrument is carried by the wind as it rises. In some cases, data are collected both during the ascent and decent of the instrument. The complete sounding is frequently referred to as a RAOB, an acronym for radiosonde observation.
The radiosonde balloon carries the instrument to about 30 000 m (100 000 ft) where the balloon bursts and the instrument parachutes to Earth. Roughly 20% of the instruments are recovered and refurbished.
See also dropsonde.
Compare rawinsonde, radiosonde observation, RAOB.Term edited 30 December 2021.
