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SODAR is a meteorological weather instrument that is used to measure the dispersion of sound waves caused by turmoil in atmosphere. The wind speed at different heights and layers just above the ground is measured with SODAR. SODAR actually stands for Sonic Detection And Ranging which is considered as a passive SONAR array. SODAR is also known by the names Sounder, Acoustic Radar and Echosounder.
During the late 1960’s, the United States National Oceanic and Atmospheric Administration (NOAA), established the practical usage of acoustic sounders with the Doppler SODAR.
SODARs have antennas that receive and transmit acoustic signals. The SODAR antenna systems are of two types, ‘mono-static’ and ‘bi-static’. The temperature fluctuation of a mono-static system determines the weather atmospheric spreading. On the other hand the bi-static system measures by both temperature fluctuation as well as wind velocity fluctuation.
Operating a mono-static SODAR involves a simple process and larger altitude coverage. For this compactness and easy operation, the mono-static SODARs are widely used all over the world.
SODAR systems have several advantages. The main advantage of the system is that it can be installed in a very short time. 500 ft. is the standard height limit for the meteorological towers, whereas SODAR systems measurements reach beyond this limit and provides accurate reading. The cost of installing SODAR is comparatively low.
In spite of all these advantages SODAR do have some drawbacks. During heavy precipitation, the measurements are not always correct and reliable.
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