(203)
grammetry for the splendid work which he has performed in preparing these
testing specifications.
Dr. K. Pestrecov, U.S.A.
When Mr. P. D. Carman, Secretary of Commission I, invited me to pre
sent this summary, I accepted the invitation as an honorable assignment, which,
I believed, would not require much effort on my part. Soon I found it other
wise.
The task would be easy in a country where photogrammetric activities
are either concentrated in one organization or are controlled by one auto
cratic body. The situation in this country is entirely different. Here numerous
governmental and private organizations are engaged in theoretical and prac
tical photogrammetry, but none of them occupies a position from which it
could dictate to all others. These conditions encourage diversity of procedures,
interpretations, and opinions, and they create serious obstacles to any unifica
tion and standardization. The situation is further complicated by the tremend
ous amount of new research material which often reveals faults in previously
established concepts without necessarily leading to new workable concepts.
After giving much thought to this situation, I was almost ready to give up
as hopeless the task of presenting a summary of the American point of view.
Then I was lucky enough to realize that the calibration practices of the Nation
al Bureau of Standards are a highly representative condensation of the Amer
ican point of view, and that there are two excellent documents which provide
an authoritative basis for a summary of this view. These documents are:
Chapter XVII, “Nomenclature and Definitions”, of the Manual of Photogram
metry x ), and the Military Standard on Photographic Lenses * 2 ).
I am telling this personal story not because it is important in itself, but
because it may suggest a foundation which could be successfully used to bring
about a national and an international agreement on standardization of con
cepts, terminology, and practices of calibration of photogrammetric cameras.
Since the Manual of Photogrammetry, the Military Standard, and the
complete description 3 ) of the Bureau of Standards procedures are generally
available, it is not necessary (and hardly possible within the time allowed) to
attempt here a review of this material. I feel that the purposes of our discourse
can be served better by my bringing to the fore a few fundamental factors
pertaining to the American point of view and its relation to the views expressed
in the international proposal.
Paramount in the American photogrammetric scene, to my mind, is the
fact that the “Nomenclature and Definitions” of the Manual of Photogramme
try and the Military Standard are the results of the tremendous efforts of a
large group of organizations and individuals whose aim was to provide, for
x ) American Society of Photogrammetry, “Manual of Photogrammetry” (Preliminary Edition),
Pitman Publishing Corp., New York and Chicago, 1944.
2 ) Munitions Board Standards Agency, “Military Standard Photographic Lenses”, MIL-STD-
150, 23 October, 1950, U.S. Government Printing Office, Washington, D.C.
Note: This standard is in agreement with the practices sanctioned by the various standards
published by the American Standards Association.
3 ) Washer, F. E. and Case, F. A., “Calibration of Precision Airplane Mapping Cameras”,
Journal of Research of the National Bureau of Standards, Vol. 45, p. 1—16, July 1950.