Fig. 1. Principle of topography measurement system with relative angle difference. (a) Top view of measurement system; (b) diagram of catwalk measurement

Fig. 2. Laser spot array obtained by CCD

Fig. 3. Schematic for scanning process on measured surface

Fig. 4. Reconstruction results with Gaussian noise (σ=0.2″). (a) Simulated surface to be tested; (b) reconstruction with CuRe method; (c) reconstruction with Zernike wavefront

Fig. 5. Two different curved surfaces for simulation. (a) Z1; (b) Z2

Fig. 6. Comparison of reconstructed surface Z1 and residual errors with Gaussian noise (σ=0.2″). (a) Reconstruction result with proposed method; (b) reconstruction result with Zernike wavefront method; (c) reconstruction result with SLI method; (d) reconstructed residual error of proposed method; (e) reconstructed residual error of Zernike wavefront method; (f) reconstructed residual error of SLI method

Fig. 7. Comparison of reconstructed surface Z2 and residual errors with Gaussian noise (σ=0.2″). (a) Reconstruction result with proposed method; (b) reconstruction result with Zernike wavefront method; (c) reconstruction result with SLI method; (d) residual error of proposed method; (e) residual error of Zernike wavefront method; (f) residual error of SLI method

Fig. 8. Reconstruction error statistics at different noise levels (σ=0-1 μrad). (a) 200 mm×200 mm, 17×17 sampling points; (b) 200 mm×200 mm, 34×34 sampling points; (c) 400 mm×400 mm, 34×34 sampling points

Fig. 9. Four repeated test results for small aperture optical component. (a) Topography measured by interferometer; (b)-(e) reconstruction results of proposed method; (f)-(i) reconstruction results with Zernike wavefront method

Fig. 10. Two repeated test results for large aperture optical component. (a)(d) Topographies measured by interferometer; (b)(e) reconstruction results of proposed method; (c)(f) reconstruction results with Zernike wavefront method

Fig. 11. Comparison of corresponding rows between reconstruction results of proposed method and topographies measured by interferometer. (a) y=75 mm; (b) y=175 mm

Table 1. RMSE statistics of repeated test for two different mirrors