Simultaneous Relative Orientation of Multiple Cameras

There are two groups of solutions to the problem of analytical aerotriangulation. The first group uses a cantilever extension technique based on independent triangulation of two-photograph models that can then be assembled into strips and blocks. The second group uses, simultaneously, all the data available to reconstruct mathematically the bundles of rays forming the photogrammetric system. Although the second approach represents the best statistical approach, it has not gained as much popularity as the first group, because of the great number of normal equations to which this approach leads. A compromise based on independent triangulation of models involving more than two photographs has distinct advantages. The solution developed by Elassal, based on simultaneous relative orientation of multiple cameras, reconstructs the bundle of rays in an arbitrary space independent from the terrestrial space. The cumulative warping associated with cantilever extension is kept to a minimum by the choice of an appropriate starting point of the extension. A program based on this solution was written for an IBM 7094 computer and can handle up to fifteen photographs simultaneously.