Abstract: A multi-section helicopter-borne rotatable beam for supporting at either of its ends range-finder cameras and television focusing cameras for stereophotogrammetric surveys, in which the central tubular section is rotated by means of an electric motor and return springs and supported by two collars mounted rotatably by means of hinged constraints on a base fixed rigidly to the floor of the helicopter cab and the two truncated-cone tubular-structure side sections of the beam are secured to the central section by a telescopic coupling arrangement ensured by half-ring ties co-operating with flanges of the sections and by through pins and safety split pins, the above-mentioned cameras being supported by prismatic box frames in their turn supported, by means of a dampening system comprising springs and double-acting shock absorbers, inside housings or pods with a ventral opening, which can be closed with an internally-sliding door, and a plexiglass portable. Variants are also envisaged.

Abstract: Heliborne beam for supporting at its two ends metric photocameras suitable to industrial stereophotogrammetric surveys, constituted by a plurality of cylindrical tubular sections linked in sequence with each other by means of flanges, and supported manually rotatable, but not longitudinally sliding with their center section inserted inside three clamp collars mounted, through double-effect cylindrical shock absorbers, on a base or bench fastened on to the floor of helicopter's cabin; at the end of the beam, two cylindrical housings with aerodynamic closure elements and provided with "eyelid" door, inside which the photocameras are supported by means of a frame linked to the housing by means of two respectively radial and axial shock absorbing units, and provided with two inner guides into which the side supporting pins of the said photocamera are inserted.

Abstract: "Three-conical" signal for industrial surveys stituted by a vertical transparent cylinder, inside which two conical axial cavities are excavated, unsymmetrical, opposite to each other, and painted in luminescent orange color, whose vertices are connected by a vertical cylindrical bore; said vertical cylinder is supported by a base which supports in its turn within the lower conical cavity a parabolic reflector and a lamp, and is provided atop with a conical cap axially provided with a small transparent vertical cylinder, ending with a sharp conical top, and being provided in its lower portion with a surface having the shape of a spherical cap.

Abstract: A method for the stereophotogrammetric survey of a large-dimension object is provided in which the object and a chain having two reference markers thereon spaced apart at a known distance are photographed from a height of about 30 m with two synchronized metric photographic cameras spaced apart by about 6 m. Depth measurements (Z axis) are made on a stereoscopic model reproduced by a stereoplotter at eight sets of points grouped in the eight conventional perimetral locations of photogrammetric orientation at the crests and troughs of the ripples or undulations of the water or ground, respectively. The mean of the depth measurements is calculated to determine the mean horizontal plane and the model is correctly orientated with respect to the horizontal plane by suitable rotation.