Fig. 1. Boundary layer focusing effect diagram

Fig. 2. Schematic diagram of the method for measuring the actual focal length

Fig. 3. The relationship between flight Mach number and the equivalent focal length of the boundary layer as a negative lens

Fig. 4. The relationship between flight altitude and the equivalent focal length of the boundary layer as a negative lens

Fig. 5. Schematic diagram of boundary layer effect simulator based on liquid spatial light modulator

Fig. 6. Experimental diagram of performance verification of a spatial light modulator simulating boundary layer effects

Fig. 7. The phase distribution gray scale and the light spot received by the camera

Fig. 8. The original laser spot image and energy distribution before pretreatment

Fig. 9. Spot image and energy distribution after grayscale adjustment and median filtering

Fig. 10. Hough transform circle fitting flow chart of spot radius

Fig. 11. Curve of theoretical and experimental effects of boundary layer effect simulation under different flight states

Fig. 12. Boundary layer simulation error curve based on spatial light modulator