ABSTRACT
THE INTEGRATION OF PHOTOGRAMMETRY AND ELECTRONIC
DATA PROCESSING EQUIPMENT FOR HIGHWAY DESIGN
by Frederick J. Doyle
Highway planning by photogrammetric means starts with an
annotated mosaic on which preliminary route studies are made.
The same photography is used to prepare a topographic map
from which alignment, grade, and earthwork are estimated for
alternate routes. When the best route is selected new large
scale photography is obtained along the preferred route.
Alignment sheets are prepared and transverse profiles are
determined in the stereoplotter at standard intervals. From
these data final design quantities are computed by standard
engineering methods,
Attachments are available which automatically record the
center line offset and elevation for cross section notes read
in the stereoplotter. The output from these units serves
directly as input to the electronic digital computer.
Electronic computation has practically eliminated hand
calculation from the highway design procedure. Alignments,
grades, profiles, design templates, cross sections, and mass
diagrams are computed in terms of rectangular coordinates.
These are printed out in tabular form and also punched on
cards or tape. The latter are fed directly to an automatic
line plotter, thus eliminating much of the tedious drafting
formerly required,
A few organizations have introduced aerial triangulation
as part of the standard procedure. The adjustment of such
triangulation is also accomplished in the electronic computer.
Analytical techniques have been developed for simul-
taneous solution of all photographs in a project. Although
reading image coordinates in a stereocomparator is not much
faster than performing the triangulation in a first order
plotter, work is under way in automatic image matching and
point measuring.
The STEREOMAT, produced by Benson-Lehner Corporation, is
an attachment to a standard plotting instrument which will
automatically perform relative orientation, plot contours,
and draw profiles. Components of the INTEGRATED MAPPING
SYSTEM, manufactured by Fairchild Camera and Instrument
Corporation, will store profile data on tape and produce an
orthophotograph which has the same planimetric accuracy as a
map. The combination of these systems will eliminate the re-
maining handwork in the photogrammetric electronic highway
design procedure.
