Moire methods for measurement of displacement and topography

Abstract

Moire is a well-known and old phenomenon. The paper is dedicated to the moire grating properties and to the principles of its origin. The methods used for their description and evaluation are also introduced. A part of the paper deals with questions on measurability of various physical intensities by the moire methods. Spheres of possible uses of the methods are mentioned. The moire methods used, like the projection moire, the shadow moire, the in-plane moire, the moire interferometry, the microscopic moire interferometry, the holographic moire and their various modifications are discussed in the rest of the paper. The physical principles including the theoretical derivation of relations and possibilities of the technical realisation are introduced for each method. The discussion of using the methods is carried out together with the introduction of their advantages and disadvantages and the comparison of possibilities of modern usage. Many approaches to the description of particular moire methods are presented in the literature. The unified approach to the moire methods used is given in the paper.