sentences:  As the frequency of the acoustic signal is varied, strongly enhanced scattering of the radar signal occurs when the Bragg match takes place.When this occurs, the Doppler shift of the radar signal produced by the Bragg scattering can be determined, as well as the atmospheric vertical velocity.Thus, the speed of sound as a function of altitude can be measured, from which virtual temperature (TV) profiles can be calculated with appropriate corrections for vertical air motion.