le the first
ir site by
Sepi Creek
work was
mapping
Barbara,
estate de-
California.
tion maps
carmel for
Highways,
aphic map
s County,
Service.
the early
y and took
it develop-
otter (Pat.
1,735,109),
The Solar
4 couple
.
inimetering
GINEERING,
RAMMETRIC
6.
"^ PHorOo-
+111, No. i,
tereoscopic
RAMMETRIC
HOTOGRAM-
No. 4, p. 30
y, PHoro-
d. XIII, p.
1 Surveys,
GINEERING,
HOTOGRAM-
[0. 4, p. 26.
ition, The
Lens Aerial
verial Cam-
Colombia,”
> Vol. III,
a in Photo-
RIC ENGI-
hutters for
RAMMETRIC
p. 1.
Phillips, M. A., “Episodes in Tropical Map-
ping," PHOTOGRAMMETRIC ENGINEERING, Vol.
VI, p. 166.
Podeyn, G. j., Jr.
“The Fairchild Cartographic Camera,” PHo-
TOGRAMMETRIC ENGINEERING, Vol. XII,
p. 345. He
“Radar Charting, A New Application of Pho-
togrammetry,” PHOTOGRAMMETRIC ENGI-
NEERING, Vol. XIV, p. 114
Sanders, Revere G.
"Aerial: Cameras and Photogrammetric
Equipment: A Quarter Century of Prog-
ress,” PHOTOGRAMMETRIC ENGINEERING,
Vol. X, p. 136.
“Design and Construction of Aerial Cam-
eras," MANUAL OF PHOTOGRAMMETRY, Pit-
man Publishing Corporation, N. Y., Chi-
cago, 1944, p. 76.
“Elementary Elevation Determination from
Aerial Photographs,” PHOTOGRAMMETRIC
ENGINEERING, Vol. IX, p. 22; MANUAL OF
PHOTOGRAMMETRY, Pitman Publishing Cor-
poration, N. Y., Chicago, 1944, p. 450.
“Military Cameras for High Speed Air-
planes,” PHOTOGRAMMETRIC ENGINEER-
ING, Vol. VII, p. 60.
“Orient Your Stereoscope Correctly,” PHo-
TOGRAMMETRIC ENGINEERING, Vol. VIII,
p. 240,
"Stereoscopy, Its History and Uses,” PHOTO-
GRAMMETRIC ENGINEERING, Vol. XI, p.
101.
DESCRIPTION OF PHOTOGRAMMETRIC IN-
STRUMENTS BUILT BY FAIRCHILD
Stereocomparagraph
This simple stereoscopic plotting instru-
ment (see Corps of Engineers history,
Fig. 3) is used for quickly measuring eleva-
tions and for compiling vertical data such
as form lines, approximate profiles, slopes,
etc. as well as planimetric details directly
from overlapping vertical aerial photo-
graphs. Although not as precise as more
expensive and complex stereoscopic plot-
ting instruments, the Stereocomparagraph
does provide a reasonable degree of ac-
curacy depending upon the skill and ex-
perience of the individual operator. Under
ideal conditions when errors due to tip
or tilt are negligible most operators find no
difficulty. in plotting to an accuracy of
1/350 of the flight altitude. Designed for
attachment to any standard drafting arm,
the Stereocomparagraph consists of a
special mirror stereoscope, two adjustable
PHOTOGRAMMETRIC ENGINEERING
41
“floating mark’ assemblies and a precision
micrometer. The micrometer and floating
marks are. employed. to measure the paral-
lax displacements. of various points on
overlapping aerial photographs.
Rectoplanograph
A simple instrument, the Rectoplano-
graph gives the map-maker a time-saving
method for rectifying and transferring
planimetric detail from aerial photographs
to maps and charts. The Rectoplanograph
is based on the principle of the camera
lucida, with which the eye receives two
superimposed images, one from a photo-
graph and the other from a map. The
Rectoplanograph goes beyond this, how-
ever, with its double prism optical system
and with its controls which allow plotting
from any aerial photograph of 9 inches or
smaller. Photos taken with lenses from 4
to 12 inches in focal length can be used.
Magnifying Mirror Stereoscope Type F-71
Intended for field or laboratory use, the
F-71 Stereoscope is a high-quality, sturdily
constructed unit. Its optical system is
specifically designed and accurately ad-
justed to reduce eye fatigue toa minimum.
A detachable four-power binocular is avail-
able for detailed examination of small
areas.
Parallax Bar Type F-163
In use with the Stereoscope this instru-
ment makes it possible to measure differ-
ences in elevation on the spatial model
created when aerial photographs are
viewed stereoscopically. The unit consists *
of a metal bar supporting a micrometer,
two adjustable floating mark assemblies
and a drawing attachment.
Rectangular Coordinate Plotter
Consisting of a % inch thick glass
plotting area mounted on. a rigid metal
table this plotter employs an unique vernier
coordinate control system. The Plotter is
used for accurately plotting mapping data
on rectangular coordinates based on deci-
mal inch measurements or metric scales.
It can also be used for drawing grid lines
very accurately. Operating rapidly it has
an accuracy of .001 of an inch