Acoustic pulses at 85 Hz (4 m) directed vertically into the lower atmosphere have been tracked by a 36.8-MHz (8-m) pulse doppler radar. Signal-to-noise power ratios in excess of 10 dB were obtained to a height of 1.5 km in the initial tests under conditions of calm winds. This technique has the potential of providing temperature soundings of the lower atmosphere for pollution studies and short-range terminal weather forecasts.
J. M. Marshall, A. M. Peterson, and A. A. Barnes, Jr., "Combined Radar-Acoustic Sounding System," Appl. Opt. 11, 108-112 (1972)