AUTOMATIC RJfOTOGRAMMETRIC INSTRUMENTS 
Fig. 1. The T-64 Orthophotoscope. 
The U. S. Geological Survey has conducted 
several experiments to determine the effective 
mapping applications of orthophotographs 
and orthophotomaps. The feasibility of com 
piling the planimetry of an urban area from a 
1:24,000-scale orthophotomosaic was estab 
lished using a continuous-tone diazo rendition 
of the orthophotomosaic printed on a white, 
scribe-coated, scale-stable plastic. Planim 
etry on a similar diazo print of this ortho 
photomosaic was compiled in the field demon 
strating the feasibility of combining the 
compilation of planimetrie detail and its field 
review and completion. Orthophotomaps are 
being produced from an orthophotomosaic 
prepared in quadrangle map format, with a 
limited amount of added cartographic sym 
bolization and marginal information, and 
printed in several colors by lithographic 
methods. Primarily only the degree of user 
acceptance will determine the value of this 
product which employs so many new and in 
teresting techniques. 
Gigas-Zeiss Orthophotoscope 
One of the advantages of the Soviet Slot- 
Rectifier FT-Shch 1 is the application of 
projection apparatus with a very large depth 
of field and thus sharp images independent 
of projection distance. Recent orthophoto 
graphs of high quality have been obtained 
from an instrument described in “Considera 
tions on the Design of the Gigas-Zeiss 
Orthophotoscope,” by Dr. W. Bruchlacher 
and Dr. M. Ahrend, Zeiss-Aerotopograph, 
Oberkochen. This instrument is based on the 
C8 Stereoplanigraph and consists of a scanner 
(C8) with attached drive motors, control ele 
ments and impulse generator for the Z- 
motion, control desk with tape punch, and a 
reproducing projector with a control desk 
and tape reader. 
The use of the punched-tape record in the 
Gigas-Zeiss Orthophotoscope allows the pro 
file information to be recorded during the 
operator-directed profile scan in the C8 
Stereoplanigraph and later used to control 
the output in the orthoprojector. The five- 
channel punched tape does not contain ab 
solute A, Y or Z values of individual profile 
points but rather stepping orders for X, Y 
and Z. For terrain of different types the 
length of the F-step is modified by an inter- 
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