Shape measurements on large surfaces by fringe projection

Fringe projection technique was used to measure the shape of large, relatively flat surfaces of several tens of square meters. The technique consists of projecting parallel fringes obliquely onto the object and extracting its shape from the fringe pattern image observed along the object normal. The fringes are created either by imaging a grid onto the object or by illuminating the object with coherent interference fringes. The technique achieves a random noise below 1 mm on surfaces several meters large.