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A radiosonde (''Sonde'' is French and German for ''probe'') is a battery-powered telemetry instrument package carried into the atmosphere usually by a weather balloon that measures various atmospheric parameters and transmits them by radio to a ground receiver. Radiosondes may operate at a radio frequency of 403 MHz or 1680 MHz. A radiosonde whose position is tracked as it ascends to give wind speed and direction information is called a rawinsonde ("radar wind -sonde"). Most radiosondes have radar reflectors and are technically rawinsondes. A radiosonde that is dropped from an airplane and falls, rather than being carried by a balloon is called a ''dropsonde''. Radiosondes are an essential source of meteorological data, and hundreds are launched all over the world daily. Modern radiosondes measure or calculate the following variables: *Altitude *Pressure *Temperature *Relative humidity *Wind (both wind speed and wind direction) *Cosmic ray readings at high altitude *Geographical position (Latitude/Longitude) Radiosondes measuring ozone concentration are known as ozonesondes. == History == The first flights of aerological instruments were done in the second half of the 19th century with kites and meteographs, a recording device measuring pressure and temperature that was recuperated after the experiment. This proved to be difficult because the kites were linked to the ground and were very difficult to manoeuvre in gusty conditions. Furthermore, the sounding was limited to low altitudes because of the link to the ground. Gustave Hermite and Georges Besançon, from France, were the first in 1892 to use a balloon to fly the meteograph. In 1898, Léon Teisserenc de Bort organized at the ''Observatoire de Météorologie Dynamique de Trappes'' the first regular daily use of these balloons. Data from these launches showed that the temperature lowered with height up to a certain altitude, which varied with the season, and then stabilized above this altitude. De Bort's discovery of the tropopause and stratosphere was announced in 1902 at the French Academy of Sciences. Other researchers, like Richard Aßmann and William Henry Dines, were working at the same times with similar instruments. In 1924, Colonel William Blaire in the U.S. Signal Corps did the first primitive experiments with weather measurements from balloon, making use of the temperature dependence of radio circuits. The first true radiosonde that sent precise encoded telemetry from weather sensors was invented in France by Robert Bureau. Bureau coined the name "radiosonde" and flew the first instrument on January 7, 1929.〔 Developed independently a year later, Pavel Molchanov flew a radiosonde on January 30, 1930. Molchanov's design became a popular standard because of its simplicity and because it converted sensor readings to Morse code, making it easy to use without special equipment or training.〔DuBois, Multhauf and Ziegler, "The Invention and Development of the Radiosonde", ''Smithsonian Studies in History and Technology'', No. 53, 2002.〕 Working with a modified Molchanov sonde, Sergey Vernov was the first to use radiosondes to perform cosmic ray readings at high altitude. On April 1, 1935, he took measurements up to using a pair of Geiger counters in an anti-coincidence circuit to avoid counting secondary ray showers.〔〔Vernoff, S. "Radio-Transmission of Cosmic Ray Data from the Stratosphere", ''Nature'', June 29, 1935.〕 This became an important technique in the field, and Vernov flew his radiosondes on land and sea over the next few years, measuring the radiation's latitude dependence caused by the Earth's magnetic field. During the 1930s the expansion of economically important government weather forecasting services and their increasing need for data motivated many nations to begin regular radiosonde observation programs In 1985, as part of the Soviet Union's Vega program, the two Venus probes, Vega 1 and Vega 2, each dropped a radiosonde into the atmosphere of Venus. The sondes were tracked for two days. Although modern remote sensing by satellites, aircraft and ground sensors is an increasing source of atmospheric data, none of these systems can match the vertical resolution ( or less) and altitude coverage () of radiosonde observations, so they remain essential to modern meteorology.〔 Although hundreds of radiosondes are launched worldwide each day year-round, the only known fatality attributed to a radiosonde was the electrocution of a lineman in the United States who was attempting to free a radiosonde from high-tension power lines in 1943.〔"Linemen Cautioned About Disengaging Radiosonde," Electrical World, 15 May 1943〕〔http://radiosondemuseum.com/wp-content/gallery/mags/1943-radiosonde-fatality.jpg〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「radiosonde」の詳細全文を読む スポンサード リンク
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