SODAR (SOnic Detection And Ranging), also written as sodar, is a meteorological instrument used as a wind profiler to measure the scattering of sound waves by atmospheric turbulence. SODAR systems are used to measure wind speed at various heights above the ground, ae thermodynamic structure of the lower layer of the atmosphere. Sodar systems are like radar (radio detection and ranging) and lidar (light radar) systems except that sound waves rather than radio or light waves are used for detection. Other names used for sodar systems include sounder, echosounder and acoustic radar.