Doppler measurement using a pair of FM-chirp signals

We propose the use of a dual-FM chirp pulse as a transmitted signal to measure Doppler shift in addition to reflection amplitude. Although, by such the transmission, the ambiguity function becomes sensitive to Doppler velocity, i.e., the accuracy of the measured Doppler shift is improved, the sidelobe level of the compressed waveform becomes large, and then, the spatial resolution decreases. In order to solve this problem, in the paper, we propose a procedure called the "separation-compression filter (SCF)". The effectiveness of applying the SCF to the Doppler measurement is confirmed through experiments.