| Abstract: | In the land-based radar direction of aircraft it was found necessary to transfer to a large plotting screen a 10X magnification of the PPI cathode-ray tube face. An instrument was developed to do this photographically, with the projected image lagging only 15 seconds behind the latest information. A single 360-degree sweep on the PPI tube is reduced to a -inch diameter image on Eastman Type 5302 Fine Grain Release Positive Film. The resultant image is rapid-processed by the application of hot solutions in a special processing cup which restricts the liquids to a small circular area on the film.The spent solutions are quickly removed by a vacuum line and the near dry image is indexed into the projection system where an air pressure gate completes the drying, cools the film, and holds it flat during projection.The projected image, at a magnification of over 300X, has sufficient quality to resolve all the pertinent detail of the tube face.The method is felt to have some general application. |
