ANALYTICAL AND EXPERIMENTAL COMPARISONS BETWEEN THE FREQUENCY-MODULATED-FREQUENCY-SHIFT MEASUREMENT AND THE PULSED-WAVE-TIME-SHIFT MEASUREMENT DOPPLER SYSTEMS

In previous publications, a new echo-ranging Doppler system based on t ransmission of repetitive coherent frequency-modulated (FM) sinusoids in two different implementations was presented. One of these implement ations, the frequency-modulated-frequency-shift measurement (FM-fsm) D oppler system is, in this paper, compared with its pulsed-wave counter part, the pulsed-wave-time-shift measurement (PW-tsm) Doppler system. When using transmitted PW and FM signals with a Gaussian envelope, the parallelism. between the two systems can be stated explicitly and com parison can be made between the main performance indices for the two D oppler systems. The performance of the FM and PW Doppler systems is ev aluated by means of numerical simulation and measurements of actual fl ow profiles. The results indicate that the two Doppler systems have ve ry similar levels of performance. (C) 1996 Acoustical Society of Ameri ca.