Shadow moireprofilometry using the phase-shifting method

Two-stages are planned to measure the 3-D profile of objects by using the phaseshifting method, based on shadow moiretopography. The stages essentially consist of moving the grating vertically, which produces a change in the moirepattern, and rotating the grating, which results in a constant phase shift regardless of the moirefringe order. In practice, an additional stage of moving the grating horizontally has to be added, which averages the grating period and yields a better moirepat- tern. We aim to improve the shortcomings inherent in the conventional method, such as complicated operation of the optical arrangement, and our emphasis is on describing the novel methodology and justifying it by an error simulation test. The experimental results show that this tech- nique is available for practical applications. © 2000 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(00)00408-6)