Fig. 1. Structural schematic of polarization lidar

Fig. 2. Simulation of 532 nm and 1064 nm polarization lidar detection range under different visibility conditions. (a) Daytime; (b) Night-time

Fig. 3. Diagram of lidar scanning in different environments. (a) Moun-tain, many obstacles; (b) Grassland, wetlands, fewer obstacles

Fig. 4. Flowchart of scanning and data processing strategy

Fig. 5. Variation of height deviation and range deviation with detection range at different elevation angles

Fig. 6. Gaussian plume simulation results. (a)-(e) Atmospheric stability B, average wind speed of 1 m/s, concentration distribution map at 0 m, 50 m, 100 m, 150 m, and 200 m; (f)-(j) Atmospheric stability C, average wind speed of 5 m/s, smoke concentration distribution diagram at 0 m, 50 m, 100 m, 150 m, and 200 m

Fig. 7. Lidar installation position and site photos

Fig. 8. Lidar scanning pseudo-color images

Fig. 9. Lidar installation position and site photos

Fig. 10. Pseudo-color map of range calibration signal obtained from background spectrum scanning measurement

Fig. 11. Fire point recognition. (a) Pseudo-color images of depolarization ratio obtained by scanning measurements; (b) Profile of depolarization ratio obtained by single radial measurement

Table 1. Main technical parameters of the polarization lidar

Table 2. Simulation parameters of lidar detection performance

Table 3. Table of national standard diffusion para-meters