Abstract: The process provides for coordinating several images of the same object obtained by transparency projection or photographic like reproduction on one or more image planes from at least two sources, by spatially positioning each image, the exact position of the rays contributing to form the image. A set of at least five points, called "markers", four located in a same plane, and one outside, can be associated to the object. The traces of these markers on the various images can then be used to define the location of the sources and image planes in relation with the marker system. In a more general approach, a required number of identifiable points of the object, but of unknown position, may be used to fully characterise locations in space.

Abstract: The shape and position of objects in space can be reconstructed from at least two projections of these objects as obtained by transmission of waves influenced by their passage through said objects.The method includes determining for each point of the projections the distance traversed through an object by each ray derived from each of the sources, in determining the volume which contains the object and the rays which are derived from the at least two sources and pass through said object, in plotting the distances traversed by the rays within the object from external limits of the volume containing the object to define a first space which is located within the object, then in plotting the distances from the external limits of the first space to define a second space which is necessarily located outside the object but within the initial volume, and so forth.

Abstract: According to the process signals adapted to the medium and to the kind of discontinuity to be analyzed are transmitted towards the discontinuity from a number of transmitting points located on at lease one base line, these signals are received at a number of reception points located on at least one base line placed on the opposite side of the discontinuity as far as the transmission paths are concerned; the received signals are then analyzed to obtain the position and shape of the discontinuity. In certain cases the echos and backscatter are also analyzed. At least one of the base lines F.sub.1 carrying the transmission points does not intersect with at least one of the other base lines carrying the reception points. This system and method may be used to determine the position and shape of underground discontinuities, to analyze the internal structure of human or animal bodies, or any other inanimate object in any medium.