Fig. 1. Schematic of carrier modulated lidar system

Fig. 2. Echo signals of traditional pulse and Gaussian pulse modulated by cosine signal with different attenuation coefficients of sea

Fig. 3. Echo signals with different pulse widths and modulation frequencies of (a) 0.1 GHz, (b) 0.5 GHz, and (c) 1.0 GHz

Fig. 4. Echo signals at different modulation frequencies

Fig. 5. Echo signals at different modulation depths with modulation frequency of 0.5 GHz and pulse width of 40 ns