Abstract: A photogrammetry target (cube or other shape of known dimension with reference points in known relation to each other) is placed on or in close proximity to a surface for which surface profile and/or surface strain are to be measured. Identifiable reference points are applied to the surface of interest, and multiple images of the surface with photogrammetry target are taken. At least some of the reference points on the photogrammetry target and the surface of interest must be visible in each image. The surface profile and/or surface strain are determined from the images based on the reference points therein.

Abstract: A method and apparatus for measuring strain distribution on a deformed surface utilizes a video or photographic camera for taking two images of the surface which are taken at an angle to each other. The surface carries a deformed grid which has grid points that are digitized using images from the camera. The digitized points each form one set of two-dimensional coordinates. Each point of the one set of coordinates is correlated with a corresponding point of the other set. The two sets of two-dimensional coordinates are then used in conjunction with the geometrical relationship between the images to calculate a single set of three-dimensional coordinates for the grid points. The three-dimensional coordinates are then used in groups of three adjacent points to calculate strain over the surface.