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Atmospheric lidar is a class of instruments that uses laser light to study atmospheric properties from the ground up to the top of the atmosphere. Such instruments have been used to study, among other, atmospheric gases, aerosols, clouds, and temperature. Atmospheric lidars belong the more general class of Lidar instruments that use light to detect the distance of objects. == History == The basic concepts to study the atmosphere using light were developed before World War II. In 1930, H.G. Synge proposed to study the density of the upper atmosphere using searchlight beam . In the following years, searchlight beams were used to study cloud altitude using both scanning and pulsed light.〔R. Bureau: La Météorologie 3, 292 (1946)〕 Advanced techniques to study cloud properties using scattered light with different wavelengths were also proposed. With the first experiments, light scattering patterns were observed in the troposphere that were not compatible with a pure molecular atmosphere. This incompatibility was attributed to suspended haze particles. Similar techniques were also developed in the U.S.S.R. The searchlight beam technique continued to improve after the end of the War, with more precise instruments and new atmospheric parameters, like temperature At the same time, pulsed light was used to construct a rangefinder to measure the distance of objects, but remained only an experimental design. In 1960, T. Maiman demonstrated the first functional laser at Hughes Research Laboratories. The demonstration was a pivotal moment for lidar development. Soon afterwards, engineers at Hughes Aircraft Company developed a laser rangefinder using ruby laser light.〔 The new device, named colidar (coherent light detection and ranging), gained widespread publicity .〔 〕 In 1962, T. Smullin and G. Fiocco used a ruby laser to detect echoes from the Moon. During their experiments they observed light scattered in the upper atmosphere that they attributed to dust particles. Soon, several research groups constructed similar devices to observe the atmosphere. By 1969, “over 20 lasers were in use by meteorologists in the United States on at least a semi-routine basis” for various applications including aerosol measurements, sub-visible cirrus and noctilucent clouds observations, and visibility measurement 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「Atmospheric lidar」の詳細全文を読む スポンサード リンク
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