Abstract: A method and apparatus for navigation of a vehicle travelling over a terrain in which the changes in elevation of the vehicle are continuously measured, in addition to the distance and heading. The distance measurements are continuously corrected by the changes in elevation in determining the instantaneous location of the vehicle with respect to a known point. The approximate location can also be obtained from a satellite GPS (global positioning system). The measured elevation may also be compared with the elevation in reference data, such as data in a three-dimensional map of the area to prevent the accumulation of errors or to make the determined location more precise.

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 data plotter includes a table for supporting a record sheet, a carriage movable thereon along one orthogonal axis, and a recording device carried by the carriage and movable with respect thereto along the other orthogonal axis. Relative movement is effected between the carriage and table by means of a drive including a pair of spaced racks mounted on one, each meshing with a motor-driven pinion mounted on the other. The data plotter further includes an electronic synchronizing system for synchronizing the operation of the two motors driving the two pinions along the two racks.

Abstract: A distance-measuring device, comprises a housing; a flexible measuring tape reelable into and out of the housing for measuring lengths; a shaft encoder rotatable by the flexible-measuring tape when reeled into and out of the housing and outputting digital pulses for each unit length of the measuring tape so reeled into or out of the housing; and an up/down counter adding the electrical pulses outputted when the tape is reeled out of the housing, and subtracting the electrical pulses outputted when the tape is reeled into the housing, and thereby providing an indication of the length of the measuring tape reeled out of said housing. Also described is a device for measuring the two coordinates of a point in space, by providing two such housings mounted on a common base, and a flexible measuring tape reelable into and out of each housing at locations spaced a predetermined distance between the two housings, the two tapes being connected at a single connection point whose coordinates are to be determined.

Abstract: A measuring stylus comprises a holder movable over a medium to be measured by the stylus and a lens floatingly mounted in the holder and biased to engage the measured medium. The underface of the lens engaging the medium is formed with a curved surface to provide a small area of contact with the medium, and is further formed with a visual measuring mark on the small area of contact with the medium.

Abstract: An X-Y table particularly for use as a plotter comprises a displaceable head including a holder for a working implement and X-axis and Y-axis carriages for displacing the head along the respective axis of the table. The displaceable head includes a second holder for a second working implement on the opposite side of the displaceable head, whereby either working implement may be selectively enabled to permit substantially the complete tabel area to be used for working purposes.

Abstract: A system for positioning an X-axis carriage and a Y-axis carriage comprises two flexible coupling elements for the X-axis carriage, and a single flexible coupling element for the Y-axis carriage. Providing two such coupling elements for the X-axis carriage enables shorter-length elements to be used, thereby providing higher dimensional stability under load or temperature variations, and also higher-load capabilities than when a single flexible coupling element is used for the respective carriage. Further, several preferred embodiments are described wherein each of the flexible coupling elements occupies a single plane, thereby enabling belts, rather than cables, to be used, further enhancing the dimensional stability and strength of the system. Still further, in all the described arrangements, the transmission ratio of the two X-axis coupling elements and of the single Y-axis coupling element are all the same, thereby obviating the need for different transmission elements to equalize the transmission ratios.