Fig. 1. Schematic of Scheimpflug imaging

Fig. 2. Relationship among measurement parameters. (a) Relationship of camera pixel points with measurement distance and distance resolution; (b) relationship of camera pixel points with backscattering angle and angle resolution

Fig. 3. Schematic of diffusion circle

Fig. 4. Relationship between depth-of-field and distance resolution of pixel points

Fig. 5. Schematic of experimental system

Fig. 6. Relationship between beam refraction and detection distance. (a) Schematic of light refraction; (b) relationship between pixel points and detection distance

Fig. 7. Intensity curves of water Scheimpflug lidar and intensity curves of backscattered light with different exposure time when tap water used as medium. (a) 1 s; (b) 5 s; (c) 10 s; (d) 14 s

Fig. 8. Scattered signal intensities of different measurement media. (a) Deionized water; (b) tap water; (c) river water

Fig. 9. Beam width diagrams obtained from three water body measurements. (a) Deionized water; (b) tap water; (c) river water

Fig. 10. Flowchart of laser beam width data processing

Fig. 11. Laser beam width and its standard deviation versus measurement distance for three different water bodies

Fig. 12. Scatter plots of initial beam width, beam width decay rate, and scattered light intensity decay rate for three different water bodies

Fig. 13. Filter membranes obtained from filtration for three different water bodies