Fig. 1. Flowchart of three-point arcsine algorithm

Fig. 2. Sketch of calculating scannig increment

Fig. 3. Scanning increment calculation error with linear disturbance

Fig. 4. Scanning increment calculation error with sinusoidal disturbance

Fig. 5. Scanning increment calculation error with random disturbance

Fig. 6. Calculated scanning increment with 3P-Asin algorithm

Fig. 7. Residual errors of reconstructed topography of step

Fig. 8. Captured one interferogram of measuring step

Fig. 9. Calculated scanning increment

Fig. 10. Measured profiles of step （Insets are enlarged profiles circled with dashed lines）

Fig. 11. Measured step heights

Fig. 12. Diverse surface reconstructed with 3P-Asin algorithm

Fig. 13. Measured step heights under sinusoidal disturbances with different amplitudes