Fmcw frequency-sweeping method and fmcw lidar system

A Frequency-Modulated Continuous Wave (FMCW) frequency-sweeping method applied to a laser Light Detection and Ranging system, the method comprising:

• obtaining a frequency-sweeping light beam, wherein the frequency-sweeping light beam periodically implements N continuous chirps within a plurality of preset frequency-sweeping measurement periods, N is a positive integer, and N≥2, each of the N chirps comprises one frequency-ascending stage having a preset frequency-ascending slope and one frequency-descending stage having a preset frequency-descending slope, the one frequency-ascending stage and the one frequency-stage are continuous, and a frequency-sweeping bandwidth of each chirp and a preset frequency-sweeping total bandwidth satisfy following relationship;
• fs=fBw/N, few is the preset frequency-sweeping total bandwidth, fs is the frequency-sweeping bandwidth, a duration of each frequency-ascending stage or each frequency-descending stage and the preset frequency-sweeping measurement period satisfy the following relationship;
• Ts=T0/2N, wherein T0 is the preset frequency-sweeping measurement period, and Ts is the duration of each frequency-ascending stage or each frequency-descending stage.