Among these areas are:
1. The serial conduct of aerial triangulation in a first
order plotting instrument.
2. The orientation of photographs and the plotting of
planimetry and contour lines in the stereoplotting instrument.
3. The reading of spot elevations for the determination
of cross section data.
To what extent can these operations be automated? Actually
each of these problems has been attacked, though not directly
within the framework of a highway design system.
As a consequence of the application of photogrammetry to
ballistic missile tracking, elegant digital computation systems
for conducting aerial triangulation have been devised by Hellmut
Schmid and Duane Brown. These programs will compute the space
position and orientation of all photographs in a project
simultaneously. At the same time they will determine the
ground survey coordinates of all points whose images have been
measured on the photographs. The systems are sufficiently
versatile to include vertical and horizontal ground control
points, and any auxiliary data controlling the orientation or
position of the exposure stations.
The input data for such a system are the image coordinates
of points measured on the photograph. These are obtained from
instruments like the Nistri or Wild stereocomparators. These
machines deliver the photo coordinates on punch cards or tape
for immediate input to the computer,
Unfortunately, at the moment, the observation time at such
an instrument does not differ appreciably from that required at
a first order plotting instrument. However, progress is being
made in the automatic matching and marking of images. And
automatic measuring of well defined point images is already in
hand. Consequently, one may expect that in the near future the
human operation will be restricted to the selection of the
general area on the photograph in which pass points are required
and to the precise identification of ground control points.
Another development of compelling interest is illustrated
in Figure 6. The Automatic Scanning Correlator (AUSCOR), as
this device was originally called, was designed and built by
Mr. G. L. Hobrough of Photographic Survey Corporation in Canada.
Under the name Stereomat it is now being developed by Benson-
Lehner,
Basically the Stereomat is a set of attachments to a con-
ventional double projection stereoplotting instrument. Servo
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