Title: Review of paper "Application of Parametric Speakers to Radio Acoustic Sounding System" by Ahoro Adachi and Hiroyuki Hashiguchi.
Abstract: General Comments This paper discusses operation of a Parametric Acoustic Array (PAA) speaker along with an L-band Wind profiler resulting in a Radio Acoustic Sounding System (RASS) to obtain height profiles of atmospheric virtual temperature.RASS consists of a wind profiling radar and collocated acoustic sources.Acoustic excitation is generated at a wavelength that is half of the radar transmission wavelength, so as to obtain echoes by means of Bragg scatter from the propagating acoustic wavefronts.As the sound speed generally decreases with altitude in the troposphere, the frequency of excitation required for obtaining radar backscatter at different altitudes is different in order to keep the wavelength relationship with the radar transmission.Therefore, an FM-chirped acoustic pulse is normally employed to expand the height coverage of RASS observations.