Phase unwrapping method based on Zernike polynomial and WKF

Abstract

The invention discloses a phase unwrapping method based on a Zernike polynomial and a WKF, and the method comprises the steps: building a space dynamic model of a wrapped phase through a Zernike polynomial fitting method, and calculating an undetermined Zernike polynomial coefficient in the model through the WKF. In order to suppress the influence of large noise points on the WKF, the high noise points are removed from subsequent WKF calculation through a method of calculating a wrapped phase quality diagram, and the stability is further improved to cope with the extreme situation of WKF divergence. High precision and stability can be achieved in a high-noise environment.

Description

technical field [0001] The invention belongs to the technical field of interferometry, and in particular relates to a phase unwrapping method of Zernike polynomial fitting and Wrapped Kalman Filter (Wrapped Kalman Filter, WKF). Background technique [0002] The phase recovery method of interference fringe pattern is the key technology to ensure the accuracy of interferometry, and the phase unwrapping is the key step of most phase recovery methods. Most of the phase recovery methods will introduce the arctangent function, so that the calculated phase is wrapped between (-π, π], and the phase unwrapping is to further restore the calculated wrapped phase to the real phase without interval restrictions . [0003] At present, the research on phase unwrapping methods at home and abroad can be divided into two categories: path-tracking algorithms and path-independent algorithms. The path tracking algorithm is characterized by satisfying the condition that the integral result has ...

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Problems solved by technology

[0004] However, the robustness of the above algorithms in the presence of large noise is relatively poor

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