OPERATIONAL EVALUATION OF EN-29A PHOTOGRAPHIC PROJECTION PRINTER (ORTHOPHOTOSCOPE)
Abstract
The Photographic Projection Printer EN-29A, or Orthophotoscope, was tested under operational conditions to determine the horizontal accuracy and photo quality of the orthophotograph, the problems likely to be encountered during extended operation of the instrument, and the adequacy of performance in possible future applications. Seven areas of representative terrain and cultural features were compiled and evaluated in terms of photo-image quality. One orthophotograph was prepared and the image positions measured to determine the horizontal accuracy of the instrument. Two orthophotograph compilations, each comprised of 12 stereo models, were processed by a photo-masking technique to transform the photos into map line-type images and printed experimentally a map substitutes. Tests indicate that the Orthophotoscope has the capability for transforming 1:50,000 scale perspective photography into orthophotographs meeting National Map Accuracy Standards for reproduction scale 1:50,000. The same criterion can be roughly applied for other scales on a 1:1 basis if the elevation differences within the photograph area are not too large. The Orthophotoscope produces the equivalent of constant-scale photographs which may be processed for rapid creation of map substitutes. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1962
- Accession Number
- AD0286243
Entities
People
- Richard F. Gettys
Organizations
- Naval Oceanographic Office