Computer Recognition and Analysis of Photogrammetric Targets

Abstract : This Technical Memorandum is a continuation of earlier work into the application of photogrammetric techniques for the modal analysis of vibrating structures. Methods are developed for the computer processing of photogrammetric negatives. The negatives capture the positions of retro-reflective targets located on the vibrating structure. With the relative distances between targets known, the distorted structure can be reconstructed. All targets are given a Global coordinate, thus reducing the accumulation of errors over the negative. The techniques used to establish the Global Coordinate System are discussed as are the methods used to determine accurately the location of the retro- reflective targets. Photogrammetric surveys Vibration measurement Analytical photogrammetry