Fig. 1. Nonlinear effect of frequency modulation signal. (a) Time-frequency curves; (b) beat signal spectra

Fig. 2. Variations of optical frequency of local and reflected signals with time

Fig. 3. Schematic diagram of FPGA process flow

Fig. 4. Input and output waveforms of signals collected by integrated logic analyzer go through FIFO and RAM

Fig. 5. Signal waveform collected by integrated logic analyzer. (a) Spectrum of resampled signal after FFT directly; (b) spectrum of corrected resampling signal without nonlinearity

Fig. 6. Schematic diagram of FMCW lidar system based on resampling

Fig. 7. Parameters of DFB laser at different currents. (a) Spectra of laser under different currents; (b) modulation bandwidth spectrum of light source

Fig. 8. Beat frequency spectra before and after resampling of stationary target

Fig. 9. Normalized amplitude spectra of targets at different distance

Fig. 10. Distance measurement results and measurement errors. (a) Before correction; (b) after correction

Fig. 11. Imaging results of system. (a) Scene image taken by mobile phone; (b) imaging result of galvanometer scanning

Fig. 12. Standard deviation of system imaging

Fig. 13. Experimental results of velocity measurement. (a) Spectrum of signal before resampling correction when target velocity is 0.15 m·s^-1; (b) velocity measurement results before correction in range of 0.1‒0.4 m·s^-1; (c) spectrum of signal after resampling correction when target velocity is 0.15 m·s^-1; (d) velocity measurement results after correction in range of 0.05‒0.4 m·s^-1