US Patent 7814783 Sodar sounding of the lower atmosphere

A monstatic sodar system using long chirps and send-while-listening techniques employs transmitter-receiver pairs (Tw, Rw; Tv, Rv; Te, Re) that have coincident main lobes (Twm, Rwm; Tvm, Rvm; Tem, Rem). The system uses digital time domain matched filters and frequency modulated or digitally modulated (eg, BPSK) chirps. Digital frequency domain matched filtering may also be used. The matched filters generate sample streams indicative of the phase and amplitude of echo signals returned from the atmosphere after the transmission of a chirp into the atmosphere.