Fast and high precision spatial carrier frequency phase shifting algorithm based on the second order difference

摘要

A spatial carrier phase shifting algorithm based on the second-order difference (SCFPS-SD) is proposed. By numerically calculating the first and second order difference of one spatial carrier frequency interferogram (SCFI) and then using a normalization algorithm, the high accuracy of phase extraction will be obtained rapidly. Based on the original differential extraction phase (SCFPS based on derivative method, SCFPS-DM) method, the proposed SCFPS-SD algorithm does not need to calculate the carrier frequency in advance and the achieved result is not affected by the accuracy of the extraction carrier frequency algorithm. Compared with current SCFPS algorithm, the proposed algorithm reveals obvious advantage in calculation speed and precision even if the sample height, carrier frequency and noise level are greatly changed. Both advantages and effectiveness of the proposed SCFPS-SD algorithm can be demonstrated by simulation and experiment.