ABSTRACT
In traditional projection moiré topography [1,2], a transmission ruling is imaged onto the surface of the object. The projected grid lines are modulated by the object shape. This deformed ruling is then imaged by a second lens onto another identical ruling. The interference between the deformed and non-deformed grid lines produces moiré fringes, which can be interpreted as contours of equal object surface height. Deformation measurements have to be made by obtaining moiré topograms of the object in its original state and in its deformed state, followed by reconstruction of the object shape from these topograms and finally by calculating the difference between these two shape measurements.
