Fig. 1. Schematic diagram of hardware components of the measurement system

Fig. 2. Rotator with analyzer assembled

Fig. 3. Motor drive control board

Fig. 4. Flow chart for calculating β_i

Fig. 5. Correspondence between the three-color light intensity and β_ori under ideal condition

Fig. 6. Data processing flow

Fig. 7. Correspondence between the three-color light intensity and β_result under ideal condition

Fig. 8. Measurement system

Fig. 9. Light receiving system

Fig. 10. Comparison of experimental and theoretical values at different distances. (a) 0.5 m; (b) 1 m; (c) 1.5 m; (d) 8 m

Fig. 11. Experimental value error curves at different distances. (a) 0.5 m; (b) 1 m; (c) 1.5 m; (d) 8 m

Fig. 12. Error histogram at two distances of 0.5 m and 8 m. (a) Experimental error histogram; (b) partial enlarged histogram