Radiosonde (redirected from Radiosondes)

radiosonde (rā`dēōsŏnd), group of instruments for simultaneous measurement and radio transmission of meteorological data, including temperature, pressure, and humidity of the atmosphere. The instrument package is usually carried into the atmosphere by a balloon (see weather balloon); balloon-borne radiosondes reach altitudes as great as 90,000 ft (27,400 m) above the earth's surface. A radiosonde may also be carried by a rocket, in which case it is known as a rocketsonde, or dropped by parachute (usually from an aircraft), in which case it is known as a dropsonde. Instruments included in a radiosonde are typically transducers for humidity, temperature, and pressure measurements; controls to improve return signals and determine which measurements are to be transmitted to data stations; and a radio transmitter. Radar also has been used to measure and transmit meteorological data from a radiosonde. These radiosonde observations are made as often as four times daily at some meteorological stations around the globe.

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radiosonde

an airborne instrument to send meteorological information back to earth by radio

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radiosonde [′rād·ē·ō‚sänd]

(engineering)

A balloon-borne instrument for the simultaneous measurement and transmission of meteorological data; the instrument consists of transducers for the measurement of pressure, temperature, and humidity, a modulator for the conversion of the output of the transducers to a quantity which controls a property of the radio-frequency signal, a selector switch which determines the sequence in which the parameters are to be transmitted, and a transmitter which generates the radio-frequency carrier.

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Radiosonde 

an aerological instrument that measures the pressure, temperature, and humidity of the air; the values of these meteorological components are then automatically transmitted to earth by radio from various altitudes during the ascent through the atmosphere.

A radiosonde consists of sensing elements, transducers that convert the small changes of the sensing elements into electric values, coding apparatus, and a lightweight shortwave radio transmitter. The radiosonde is lifted by a pilot balloon to an altitude of 30 to 40 km. During the ascent, the radiosonde automatically sends coded signals corresponding to the instrument readings, and the signals are picked up by a radio receiver at the launching site. The operating range is approximately 150 to 200 km. There are balloon-borne radiosondes that can also measure wind velocity and direction.

Radiosondes are used extensively for vertical atmospheric sounding. The first radiosonde was constructed by the Soviet scientist P. A. Molchanov in 1930.