GB660628A - Improvements in and relating to stereo-photogrammetric apparatus - Google Patents

Abstract

660,628. Stereo-photogrammetric apparatus. WILLIAMSON, S. Aug. 12, 1949 [Aug. 12, 1948], No. 21030/49. Divided out of 660,589. Class 97 (i). In stereo plotting apparatus in which stereoscopic pairs of aerial or like photographs are projected on to a plotting table mounted on a carriage sliding on a vertical pillar for the purpose of observing the height where each point of detail is in stereoscopic correspondence at the plane of the plotting table, the height is indicated on a transparent scale, a magnified image of part of which is projected on to a conveniently mounted screen. In the apparatus described the scale is fixed and the projection system and screen carried by the carriage. As shown, the table 19, having an illuminated pin-hole 54, vertically above a plotting pencil 12 mounted as described in Specification 660,589, is supported by an arm 18 from a carriage 17 vertically movable on a pillar 16 by a rotatable screw 22 engaging a nut 31 having an arm 36, Fig. 2, passing through a slot in the pillar to engage the carriage. Supported by the pillar is a vertical scale 45 adjustable vertically by a screw 43, an image of which scale is projected upon a screen 76, Fig. 2, supported by the carriage, by means of lamp 64, condenser 68, lens 70 and reflectors 74, 75, all carried by and movable with the carriage 17 so that the height of the table above the datum surface may be readily obtained from the projected image. The pillar is supported by a horse-shoe shaped base 10 having lamps 81 for illuminating the plotting surface 14.