"Digital systems." . . "Mapping." . . "Stereoscopic map plotters." . . "AUTOMATIC MAP COMPILATION SYSTEM"@en . . . . . . . . . . . . . "Contents: Height error discriminator DC raster generator for stop motion Raster shape modulator Electronic masking DC restoration Electronic cross hairs."@en . . . . "The Automatic Map Compilation System utilizes a small digital computer which directs an analog system to the indicated ho ologous points for an estimated height on a stereo diapositive pair. An analog scan, with associated correlatio equipment, op rates to measur the height error. The detailed terrain data obtained from the scan is used to produce an orthophoto and the altitude measurement is used to produce a drop-line chart from which the contour lines can be drawn. The system analysis, mechanical design, and computer program did not reveal any serious problems. The de ign is quite straightforward although there are many areas where the stringent accuracy requirements dictated unusual solutions. The mechanical system is quite conventional, with carriage supports consisting of V-groove ways using ball b aring blocks and servomotors coupled through precision ball-nut screws and anti-backlash gears. The control system utilizes 400-cps components, thereby providing higher speed capabilities an a larger range of design components to select from. The orthophoto and drop-line chart are produced photographically, the latter by a print-out of three gray tones defining the desired contour intervals. (Author)."@en . . . . . . "Mathematical analysis." . . . . "Instrumentation." . . "Circuits." . . "Correlation techniques." . . "Aerial photographs." . . "Digital computers." . . "Electronic scanners." . . "Analog systems." . . "Altimeters." . . "Position finding." . . "THOMPSON RAMO WOOLDRIDGE INC CANOGA PARK CALIF." . . "Optical equipment." . .