Fig. 1. Schematic diagram of composition of measuring system

Fig. 2. Schematic diagram of calculating torsion angle of P1 azimuth

Fig. 3. Schematic diagram of perspective distortion

Fig. 4. Schematic diagram of solving perspective transformation matrix

Fig. 5. Schematic diagram of target image correction

Fig. 6. Measurement results of perimeter of rectangular frame

Fig. 7. Schematic diagram of ground simulation experiment

Fig. 8. Images before and after correction of P7 azimuth

Fig. 9. Target image of P1 azimuth

Fig. 10. Measurement results of fan blade torsion angle in P1~P7 azimuth

Fig. 11. Measurement results of physical distance of marker circle center