THE Rc-130A AIRCRAFT
tems together with a vastly increased cargo
capacity enables the 1370th Photo Mapping
Group to be completely self-supporting in
its field operations. In the field of photogrammetry the introduction of the RC-130A
World Mapping System into the U. S. Air
Force inventory marks a major step forward
in its operational capability.
But what of the future? Even now, while
401
these aircraft are rolling off the assembly line,
Lockheed Systems Engineers are actively
engaged in studies of more advanced systems-systems which are even more automatic and will provide even better sevenleague boots for the Air Force, in its constantly expanding task of mapping and
charting the free world.
Topographic Mapping by
Photogrammetry IS Engineering*
BROTHER B. AUSTIN BARRY,
A ssociate Professor of Civil Engineering,
Manhattan College, New York, N. Y.
ABSTRACT: Through an intensive four-year study of the status of surveying
and mapping, the A merican Society of Civil Engineers arrived at the conclusion
in early 1959 that surveying of all types is engineering a,nd is presently implementing this conclusion in several areas: its membership requirements; educational policy; and contracting for topographic mapping in a professional
manner. This last concerns photogrammetrists insofar as the recent procedure
of bidding on a competitive-price basis is now adjudged to be an unprofessional
practice and must be replaced by a negotiation procedure. The author of this
paper, having been involved in all these deliberations to date, points up the reasoning behind the ASCE conclusion that topographic mapping by photogrammetry is engineering and what must now be done to insure its professional future.
date back in recent
T history to themaps
time when it became imOPOGRAPHIC
portant for men to plan civil construction of
larger than average size, though probably
the depicting of hills and valleys, woods and
streams, and topography generally became
important first to military strategists. "Topographic" or "topography," sometimes used
erroneously to signify roads, streams, marsh,
culture, and physical landforms on a map,
here means elevation information contained
on the map by contour lines or numerical
elevation indications. Portrayal of terrain by
contour lines has been common practice for a
century, more or less, and elevations on maps
have become very reliable. Vve cease to be
astonished now at the mapping of impossible
terrain, because we know the capabilities of
aerial photogrammetric methods today.
Topographic surveying and consequent
mapping at large and intermediate scales is a
step in planning and designing works, whether
public or private, and is thus the initial step
in the engineering process. Studies are made
directly on the maps obtained, and plans for
the improvements are drawn from these
initial and subsequent larger-scale maps.
These maps then are basic engineering instruments.
It is apparent, therefore, that topographic
surveying and mapping must be reliably
done, and executed under the control of an
engineer responsible for its outcome. Since
much importance is attached thereto, one
can hardly expect the survey to be an acrossthe-counter commodity bought and sold like
a power saw or a bulldozer. "Caveat emptor!
-Let the buyer beware:"-has no place in
this type of activity.
Scale of map has some bearing, albeit
tangential, on this question: the usual engineering maps are large-scale or intermediate-scale. For geographers, maps need
not have the accuracies envisioned in this
discussion, since usually small scales
(1: 1,000,000 or 1: 5,000,000 suffice-and
without precise elevation data. But for engineering planning (l: 24,000 and larger),
* Presented at the Society's 26th Annual Meeting, Hotel Shoreham, vVashington, D, C, March
23-26, 1960.
402
PHOTOGRAMMETRIC ENGINEERING
precision and accuracy are needful-especially for design.
Because such larger-scale survey maps are
engineering vehicles, reliance must be built
into them. Our economy cannot admit of an
unreliable basis for engineering design. It is a
tribute to very many in photogrammetry
that the bulk of the surveys during the past
decades has been eminently satisfactory,
often better than anticipated. It is heartening
to be able to make this statement in an era
when the acknowledged trend in workmanship
is daily downward towards more slovenly production in almost every endeavor.
But we must admit to ourselves that instances do exist of un praiseworthy mapping
endeavor, of planimetry undeniably wrong, of
topography that did not fit the ground. These
cases give surveying by photogrammetry a
bad name and could set it back years. If you
agree with me that such instances are inexcusable, then you must subscribe to a plan
for ascribing responsibility for the topographic survey and map.
The plan is one which follows from the
ASCE statement that topographic surveying
and mapping is engineering. Inasmuch as
topo mapping is an engineering project, then
the engineer responsible for its production
must stand behind it to the full extent of his
reputation. This is the code of ethics of the
engineer. This is essential to the professional
stand. The responsibility for topographic
surveying and mapping (whether by photogram metric or by other methods) must be
centered in the hands of an engineer who is
rendering this (engineering) service.
There is a basic need today for recognition
of this responsibility of the engineer for his
topographic surveying, particularly photogram metric. A noticeable trend in recent
years to believe that topographic sUl"veys are
automatically compiled representations of the
earth's surface, entirely reliable if neatly
drawn, is a dangerous trend. The survey user
must be ed uca ted to the true cri teria of its
worth, such ingredients as extent of control,
closeness and relia bili ty of su pervision, and
quality of the work at every stage. This
lesson must be widely preached that the
topographic survey is a tailor-made product
specifically engineered to fit a special engineering purpose.
It is equally true that the people producing
the topographic survey and map must learn
this lesson fully, too. Armed with sophisticated new equipment and utilizing fabulous
time-saving methods, we must be fully con-
scious of our professional responsibility for
the final product. Along with knowledge and
ability must go honesty and integrity.
I t follows then, as a corollary to this principle of responsibility, that topographic
surveying and mapping cannot be subject to
the whims of low budget dictated by prevailing market conditions. The engineer
executing the survey and preparing such a
map must have the independence to exercise
judgment to spend enough to do the right
job. Hence the form of contract must be one
that guarantees this independence-and it
cannot be based on the lowest price.
The alternative, then, is to negotiate
topographic mapping contracts instead of
bidding them competitively. Just how this
should be done I cannot offer here in a nicely
wrapped package: there is no ready formula
waiting for use. Sufficient study has been
made, however, for me to assure you that
negotiation is feasible.
In the early days, photogrammetric surveys
were bid by men, fortunately, of high integrity. Often such a bid contract was
amended as work progressed to include an
extra sum when need was demonstrated for
extra or more precise work. Many clients
even then used a negotiation basis to assure
the best work-much as they would contract
for other types of engineering services. Today, photogrammetric topographic mapping
cannot risk continuing on an insecure basis
of competitive bidding.
The changeover suggested above to negotiated contracts is being made. It means a
change in practice and outlook, a scrapping
of certain habits and attitudes. But it also
means a rise in professional stature, assurance to the public that the surveying and
mapping it contracts for is not skimped because a bid was too low. It is a necessary step
towards full accreditation of photogrammetry by all in the engineering profession
and by the public as well.
Admittedly there will be difficulties attendant on the change: the ascribing of professional responsibility to an individual engineer
and the extent of liability; the facing of
"corporate practice" of engineering in certain states; the instilling of notions of professional conduct and business practices
compatible therewith. Here again there is no
easy way. But I do have supreme confidence
in the integrity and competence of the truly
professional man to see his way through the
momentary difficulty and come out, not
just even but far above the mediocre.