Fig. 1. Arrangement of subapertures

Fig. 2. Surface error of reference mirror

Fig. 3. Surface error of the mirror to be measured

Fig. 4. Surface reconstruction map of reference mirror

Fig. 5. Surface reconstruction map of the mirror to be measured

Fig. 6. Surface residual map of reference mirror

Fig. 7. Surface residual map of the mirror to be measured

Fig. 8. Experimental setup

Fig. 9. Measured subapertures

Fig. 10. Reconstructed full aperture map of the elliptic surface

Fig. 11. Reconstructed surface map of reference mirror

Fig. 12. Difference maps between each subaperture map and its corresponding stitching map

Fig. 13. Subaperture variations

Fig. 14. Reconstructed testing elliptic surface map with the standard Zernike polynomials fitting method

Fig. 15. Reconstructed reference surface map with the standard Zernike polynomials fitting method

Fig. 16. Difference maps between each subaperture map and its corresponding stitching map using the traditional method

Fig. 17. Subaperture variations with the traditional method