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INTRODUCTION
At the London congress in 1960 the International Society for Photogrammetry decided that a working
group on fundamental problems should be established within Commission II. The group was entrusted
to Sweden. The Swedish Society of Photogrammetry then appointed president and associates.
First the group prepared and outlined a program which was distributed to all national societies of
photogrammetry, other organizations and individuals for critical examination and proposals. A final
program was then worked out and published in Photogrammetria 1961 —1962, No. 1. As was pointed
out in the program, it was to be regarded as a survey of actual fundamental problems in photogram
metry. The entire program was not expected to be completed during the period 1960—1964. Everyone
was invited to contribute to the report of the working group.
The following resolutions of Commission II passed at the London congress were followed in carrying
forward the research.
4a. All information on accuracy should be expressed in clear and well-defined terms. This
information should include data indicating its reliability, e.g. the number of redundant obser
vations.
5. It is desired that principles for the establishment of tolerances and specifications for instru
ments and methods in photogrammetry should be worked out. For such purposes it is necessary
that the sources of error should be carefully investigated under real working conditions. More
attention therefore, should be paid to theoretical and practical investigations of the fundamental
operations of photogrammetry.
6. In order to compare the results of different theoretical and practical investigations into
instruments and methods, it is suggested that the observations be adjusted by least squares.
The research program follows the fundamental operations of photogrammetry and this report will sum
marize the results in the sequence according to the table of contents.
For practical reasons detailed and complete descriptions of individual research projects cannot be
given in this report. In many cases reference will be made to other reports where detailed information
may be found.
Microns (10 -3 mm) will in this report frequently be denoted ¿/in.
Accuracy will be expressed as root mean square value of discrepancies (s m ), standard error of unit
weight (s 0 ) and standard error (functions) (s x ) with subscript according to circumstances.
Precision will be expressed as standard deviation of one observation (s) or of the mean (s—).
ACKNOWLEDGEMENTS
We wish to express our sincere thanks to all the cooperative photogrammetrists and other interested
individuals who have contributed to the work upon which this report is based. We have attempted to
give due credit in the body of the report.
Particularly we wish to mention Svenska Reproduktionsaktiebolaget (SRA) for publication of the
report at special cost, Statens tekniska forskningsrad (the Swedish Technical Research Council) for
financial support, and GIMRADA, Ft. Belvoir, Va., U.S.A. for the contract under which much of the
basic research was performed.