Processing of underwater photographs

Underwater stereophotogrammetric survey photographs generally include no reference points and insufficient numbers of control points, preventing the use of rigorous photogrammetric processing methods. The specifics of underwater stereosurveying require some changes in methods for processing pairs of photographs. Special coordinates are determined by direct photogrammetric intersection by an analytic method involving a computer. The major stages in analytic processing of photographs include measurement of coordinates of points on the stero pairs, transformation of measured coordinates to a base coordinate system by known equations, reducing the coordinates of the points on the pair, computation of photogrammetric coordinates of object points by equations presented in the article and determination of distance between the points. The method is intended for determination of quantitative charactersitics of biological objects in oceanographic studies and can be used to study the microrelief of the sea bottom.