So the software is made to give a chart of error phase in any unequal step phase shifting,and a calibration algorithm is presented to give the correct phase based on this error phase chart.

Through the data processing, the unequal step observation sequence for deformation monitoring on the soft ground of expressway is transferred to equal step sequence.

Through the data processing, the unequal step observation sequence for expressway deformation monitoring is transferred to equal step sequence.

The structure of a simultaneous phase-shifting interferometry system based on two-dimensional(2D) orthogonal grating diffraction is analyzed in detail,including components of interference,spatial beam splitting,polarizing phase-shifting element,and image sampling and processing.

For the anti-vibration in interferometry,a new simultaneous phase-shifting method based on Michelson polarization phase-shifting technique,is presented.

A simultaneous phase-shifting interferometry is analyzed by JonesMatrix theroy.

It is important to give a range for the phase step which could be adopted in the algorithm.

The four-step phase-shifting algorithm for quantitative analysis of the Ronchigram is derived from the wave theory of Ronchi test.