Fig. 1. Geometry of laser reflection on a facet of the sea surface

Fig. 2. The process of generating photon distribution based on the Monte Carlo method

Fig. 3. Simulation process of photon-counting lidar on sea surface targets(a) spatial distribution of sea surface heights， (b) spatial distribution of normalized energy, (c) spatial distribution of BRDF at different locations,(d) number of signal photons returned from different locations

Fig. 4. Photon point cloud distribution generated based on random sea surface simulation (a) distribution of returning photons， (b) cumulative histogram of simulated photons

Fig. 5. ATLAS's photon distribution in the verification region of East Pacific

Fig. 6. Relationship between the average number of photons per single-pulse and the wind speed above sea surface

Fig. 8. Elevation biases and standard deviations for photon-counting lidars at different wind speeds (a)averaged elevation bias, (b) elevation standard deviation