Fig. 1. TDLAS flow velocity measurement system

Fig. 2. Illustration of optical path structure for velocity measurement

Fig. 3. Doppler frequency shift signal

Fig. 4. Gauge signal and calibrated relative beam results

Fig. 5. Flow velocity measurement layout schematic

Fig. 6. Flow velocity measurement system field physical diagram

Fig. 7. Curve of transmittance intensity signal of etalon versus sampling point

Fig. 8. Curve of relative wavenumber of laser tuning versus sampling point

Fig. 9. Laser absorption spectra versus relative wavenumber

Fig. 10. Plume velocity curve of solid propellant