Abstract: Method and apparatus are described for determining the contour lines for gridded data defining a four-sided cell composed of two grid lines along the X-axis and two grid lines along the Y-axis, involves the steps of sorting four data points according to their values along a selected one of the two grid axes; connecting the point of minimum value along the selected grid axis to the point of second minimum value along the selected grid axis; and connecting the point of third maximum value along the selected grid axis to the point of maximum value along the selected grid axis. In the described embodiment, the contour lines represent common elevation points in a topographic map.

Abstract: A pair of photographs of the same object taken from different positions and fixed to a single carrying plate the position of which can be adjusted in a first plane. Three measuring devices are associated with the carrying plate for determining the coordinates of the plate to indicate the distance and angle of the plate relative to a fixed reference system. Binocular optical means includes two measuring marks respectively having lines of sight intersecting said two photographs. The lines of sight are parallel to one another and lie in a plane disposed perpendicular to the first plane. One of the marks can be moved relative to the other so that the lines of sight may intersect identical points on the two photographs. A fourth measuring device is provided for measuring the distance between said lines of sight. The outputs from the four measuring devices are fed into a computer for deriving three dimensional quantitative information about the object.

Abstract: A surveying system utilizes remote-controlled flashbulbs of flashlamps which are positioned to identify objects on terrain which is overflown with an aerial camera. The firing of the flashbulbs or flashlamps by a flash actuation signal transmitted either from the aircraft or from the ground is synchronized with the camera operation for providing a photograph of the overflown terrain having highly distinctive markings corresponding to the high intensity light emitted by the flashbulbs or flashlamps.

Abstract: An apparatus for automatically adjusting the level of at least one surface point on a flexible platen of a photogrammetry apparatus having photogrammetric images projected thereon in first and second colors is disclosed as comprising means for receiving and transmitting the first and second colored images at the surface point, which is attached to and movable with the receiving and transmitting means and means for vertically positioning the receiving and transmitting means. There is also provided means for converting the transmitted colored images into electrical signals, which are proportional in strength to the intensity of the colored images, and means for controlling the positioning means in response to the electrical signals, whereby the surface point is adjusted to a position where the colored images intersect.

Abstract: A method and apparatus is disclosed for determining the height, width, leh and orientation of an object from the feature image of the object found on oblique panoramic aerial photography. A magnifying eyepiece is provided with a calibrated reticle for measuring the dimensions of the feature image. The eyepiece also has a reference mark and indicia about the eyepiece for measuring the orientation from true north of the longitudinal axis of the feature image. The actual measurements of the object are quickly determined from the measurements of the feature image using a suitably programmed calculator supplied with the photograph and camera parameters.

Abstract: An apparatus for use in photogrammetry is disclosed having two spaced-apart parallel scanning zones to which the photographs of a stereoscopic pair of photographs are mounted.A carriage mounted optical scanning system is provided for scanning the two scanning zones and for projecting images of the respective zones to a binocular viewing system, and a secondary optical system is provided, preferably on the carriage, for superimposing reference marks on the projected images.The scanning system is arranged in such a manner that simultaneous scanning of the two scanning zones can be effected in a first direction parallel to the scanning zones, and independent scanning of the two scanning zones can be effected in a second direction which is parallel to the scanning zones and orthogonal to the first direction. Also, the apparatus is adapted to permit relative scanning of the two scanning zones in the first direction or for optically moving the reference marks relative to one another in the first direction.

Abstract: A photogrammetric plotter having a photocarriage which is supported on a trolley carried by a first set of way bars which in turn are supported from the trolley element on a second set of way bars mounted on a base for viewing by binocular optical system of a pair of stereo photos on a pair of photo carriers on the photocarriage. A constraint free drive apparatus is provided for driving the photocarriage along each of the set of way bars each of constraint free drive apparatus including a drive rod supported, in a preferred embodiment on the trolley supporting the photocarriage, and at only one end of the drive rod is displaceable in a direction transverse of the longitudinal axis of the drive rod but not displaceable axially of the drive rod. A drive assembly constituted by V drive wheel and a servo motor driving the drive wheel engage the drive rod, and a clutch means constituted by a spring-solenoid controlled cam member permit the rapid engagement and disengagement of the drive rod with the drive wheel.

Abstract: An arrangement for producing photographs which may be used for photogrammetric surveys of spatial objects, in which control points are established in the spatial object. Two photographs are taken using central projections with different positions of the projection center. The control points are the component of a mobile control point system having a reference with four points with known position coordinates constituting a quadrangle. At least two space points located outside the reference plane, have unequal or identical position coordinates relative to the reference plane. At least the space position coordinates of one space point and the space position coordinates of the other space point are known, and at least six such points appear on each of the two photographs. To increase the accuracy of determining the unknown in the transformation equations, a reference plane with more than four points, preferably sixteen points, is introduced into the spatial object to be measured.

Abstract: A stereo relief modelling apparatus based on photogrammetric method and apparatus comprising a flexible platen, used with standard stereo plotting instrumentation such as double-projection direct-viewing plotting instruments. The purpose of the flexible platen is to provide an absolute stereo image for photographic, modelling and other purposes. The flexible platen, which is of sufficient size to provide a meaningful mapping surface, is vertically adjustable at a multiplicity of points by mechanical, pneumatic, electro-mechanical, fully automated, or other means to provide an actual model-like three-dimensional photographic or modelling surface to enable relief distortion from aerial photographs to be effectively eliminated in planimetric photographs which are taken of the adjusted flexible platen, or models molded on the adjusted flexible platen, upon which the aerial images are projected. Modelling is facilitated by situating the platen inside a sealable vacuum box from which the air is removable.

Abstract: A plurality of sensors of various types each initiating a marker signal as it produces a "frame" of information sensed, such as a camera film frame for example. A computer in the navigation system of the reconnaissance craft receives the marker signals and generates respective successive frame count numbers which are fed back to the proper respective sensors and recorded directly on the individual frames to whch they pertain while the frames are still being taken or sensed by the sensors. At essentially the same time as the frame count number is being processed, the computer outputs a block of information to be stored and recorded for that one frame (sensor product), this information including the identifying frame count number, the sensor which took it, the time of occurrence, and the geographical location of the event as provided by the navigation system.

Abstract: In a device for correcting, with respect to the reference plane of an object having a group of contour lines thereon, the positional deviation and variation in the reduced scale created corresponding to the height of each contour line when the object is photographed through a photographic objective, there is provided means for tracing each of the contour lines photographed on the film and generating a position signal for each of the contour lines. A correction mechanism is rotatably supported at a point (N), and has introduced thereinto the ratio between the distance (H) from the center of the photographic objective to the reference plane of the object and the distance (.DELTA.H) from any of the contour lines being traced by the signal generating means to the reference plane. The correction mechanism receives at the input side thereof the position signal from the signal generating means to generate a position signal (P') which satisfies the relation that P' = (1 - (.DELTA.

Abstract: Photogrammetric method and apparatus comprising a flexible platen used with standard stereo plotting instrumentation such as double-projection direct-viewing plotting instruments. The purpose of said flexible platen is to provide an absolute stereo image for photographic and other purposes. The flexible platen which is of sufficient size to provide a meaningful mapping surface is vertically adjustable at a multiplicity of points by mechanical, pneumatic, electro-mechanical, fully automated, or other means to provide an actual model-like three-dimensional photographic surface to enable relief distortion from the aerial photographs to be effectively eliminated in planimetric photographs which are taken of the adjusted flexible platen upon which the aerial images are projected. Additionally, an orthostereoscopic photo can be produced by the use of color film.

Abstract: A reflecting stereoscope has picture holders and oculars for the observation of pictures held by the picture holders, and an optical train between the picture holders and the oculars. Picture marks and measuring markers carrying adjustable measuring marks are interposed in the optical train and there is a measuring device for measuring the location of the measuring marks. The picture holders are disposed in the focal plane of the oculars and a lens system on the optical axis of the oculars projects the magnified image of the measuring marks onto the focal plane of the oculars. Partially reflecting mirrors in the light path of the optical train observe picture marks and the measuring marks. A special system for moving the measuring markers and measuring their position is provided.

Abstract: A device for connecting a stereocomparator to an electronic computer to set up an analytic photogrammetric plotter. In the control device of a stereocomparator, some of the stereoscopic exploring motions of the photograms for the plotting take place with a manual control, and an electronic, digital or analog computer receives information and elaborates the same to obtain additional data relating to at least one other motion. Apparatus is provided to translate said additional data into motion.

Abstract: An apparatus for measuring the elevation of a three-dimensional foreground subject which comprises the steps of determining the interrelationship of the first and second images of the three-dimensional foreground subject photographed at two different points to find minute mutually corresponding areas in two images; correcting the first photographed image according to the displacement of the corresponding areas from each other; again determining the interrelationship of the corrected first pseudo-image and the noncorrected second image; correcting the second image by said interrelationship to provide a corrected second pseudo-image; determining the interrelationship of said corrected second pseudo-image and the original second image; repeating the above-mentioned operation; when the determined displacements of the first and second images fall to below a certain value, calculating an algebraic sum of all the determined displacements of said first and second images; and finally measuring the elevation of a three