a monostatic sodar system for atmospheric sounding includes a processor and display unit that generates a set of acoustic chirps for transmission by transmitter 20 . discontinuities result in echoes being returned to a receiver of system . receiver outputs extracted echo signals on line to the processor for analysis . detector implements a fourier domain matched - filter to extract echo signals from noise . by using a set of multiple chirps of increasing length with increasing intervals between them , substantially any feasible range can be accommodated using send - then - listen techniques with the benefit of high s / n performance .