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Stereo-photogrammetric mapping instrument
276
CURRENT TOPICS
[J. F. I.
Ask Astia for technical information and bibliographic services. This new Armed Services Technical Information Agency has been organized by the Defense Department to collect, catalog, and store technical information generated by or for the military departments, and to provide bibliographic service on scientific and technical reports for military agencies and their contractors, and other authorized agencies. First task of ASTIA will be integration of technical information services performed by CADO (Central Air Documents Office) and Naval Research Section of the Library of Congress. Director is Leslie E. Neville, former Director of Public Relations for CurtissWright. Address: ASTIA, HQ, U. S. Air Force, Room 5D518, Pentagon. New Tungsten Machining Technique Developed.IA new technique for drilling, grinding, turning, milling, threading, and tapping tungsten metal using ordinary metal working machines has been,developed by Philips Laboratories, Inc., Irvington, N. Y. According to an announcement by Dr. O. S. Duffendack, President, this new technique permits the machining of tungsten metal to tolerances comparaable to those normally achieved with steel or brass. For instance, tungsten tubing has been fabricated with an outer diameter of .066 in. 4- .0005 and an inner diameter of .060 in. ± .001. An 0-80 tungsten screw ~ in. long has been made with a .025 in. hole drilled through its entire length. The Laboratory is already using this new method in manufacturing its newly developed tungsten L-cathodes for long lived electron tubes. Additional applications are expected to be found in electron tube manufacture and in the fabrication of parts of other devices which must operate at exceedingly high temperatures in a vacuum or in reducing or inert atmospheres. The new machining technique was developed by Dr. Roberto Levi, a research chemist on the Laboratory staff. Up to the present it has not been possible to make complicated shapes of tungsten, due to its extreme hardness and brittleness. Rod, wire, and sheets are its present common forms. Stereo-photogrammetric Mapping In~trument.--The I(elsh Plotter, a relatively new stereo-photogrammetric mapping instrument, has been tested and evaluated for military application at Fort Belvoir's Engineer Research and Development Laboratories. The instrument was originally designed by Harry Kelsh who was then with the Soil Conservation Service. It was further developed by the Geological Survey for use in its mapping program. The Kelsh Plotter, in principle, is similar to the Multiplex, a standard stereo-photogrammetric mapping instrument of the Corps of Engineers. Both instruments project a three-dimensional, measurable image from a stereo-pair of aerial photographs, from which a topographic map may be drawn. The Multiplex requires auxiliary equipment to correct for aerial camera lens distortion present in the aerial photograph, whereas the Kelsh Plotter has a correction device built into the instrument. Moreover, the three-dimensional image projected by the Kelsh Plotter is more highly resolved and at a greater magnification than that projected by the Multiplex. The commercial model tested by the Topographic Engineering Department at E R D L , although lacking certain desirable features, revealed a basic design favorable to military mapping applications. Accordingly, modification and further development of the instrument are being actively pursued.
CURRENT TOPICS
[J. F. I.
Ask Astia for technical information and bibliographic services. This new Armed Services Technical Information Agency has been organized by the Defense Department to collect, catalog, and store technical information generated by or for the military departments, and to provide bibliographic service on scientific and technical reports for military agencies and their contractors, and other authorized agencies. First task of ASTIA will be integration of technical information services performed by CADO (Central Air Documents Office) and Naval Research Section of the Library of Congress. Director is Leslie E. Neville, former Director of Public Relations for CurtissWright. Address: ASTIA, HQ, U. S. Air Force, Room 5D518, Pentagon. New Tungsten Machining Technique Developed.IA new technique for drilling, grinding, turning, milling, threading, and tapping tungsten metal using ordinary metal working machines has been,developed by Philips Laboratories, Inc., Irvington, N. Y. According to an announcement by Dr. O. S. Duffendack, President, this new technique permits the machining of tungsten metal to tolerances comparaable to those normally achieved with steel or brass. For instance, tungsten tubing has been fabricated with an outer diameter of .066 in. 4- .0005 and an inner diameter of .060 in. ± .001. An 0-80 tungsten screw ~ in. long has been made with a .025 in. hole drilled through its entire length. The Laboratory is already using this new method in manufacturing its newly developed tungsten L-cathodes for long lived electron tubes. Additional applications are expected to be found in electron tube manufacture and in the fabrication of parts of other devices which must operate at exceedingly high temperatures in a vacuum or in reducing or inert atmospheres. The new machining technique was developed by Dr. Roberto Levi, a research chemist on the Laboratory staff. Up to the present it has not been possible to make complicated shapes of tungsten, due to its extreme hardness and brittleness. Rod, wire, and sheets are its present common forms. Stereo-photogrammetric Mapping In~trument.--The I(elsh Plotter, a relatively new stereo-photogrammetric mapping instrument, has been tested and evaluated for military application at Fort Belvoir's Engineer Research and Development Laboratories. The instrument was originally designed by Harry Kelsh who was then with the Soil Conservation Service. It was further developed by the Geological Survey for use in its mapping program. The Kelsh Plotter, in principle, is similar to the Multiplex, a standard stereo-photogrammetric mapping instrument of the Corps of Engineers. Both instruments project a three-dimensional, measurable image from a stereo-pair of aerial photographs, from which a topographic map may be drawn. The Multiplex requires auxiliary equipment to correct for aerial camera lens distortion present in the aerial photograph, whereas the Kelsh Plotter has a correction device built into the instrument. Moreover, the three-dimensional image projected by the Kelsh Plotter is more highly resolved and at a greater magnification than that projected by the Multiplex. The commercial model tested by the Topographic Engineering Department at E R D L , although lacking certain desirable features, revealed a basic design favorable to military mapping applications. Accordingly, modification and further development of the instrument are being actively pursued.