mA
RESULTS OF EXPERIMENTAL PLOTTING FOR
1:50,000 MAPS
by T. J. BLacuuT
National Research Council of Canada
President, Commission IV—3, ISP
INTRODUCTION
The photogrammetric technique of producing maps is a complex operation, and
although this technique has been in use for several decades, there are many funda-
mentals which still have not been sufficiently studied. Research centers and larger
mapping agencies have tried to improve on this situation by initiating theoretical and
experimental research programs, which have without a doubt made important contri-
butions to modern mapping technique in recent years. Most of these contributions
have been achieved through the concentrated effort of individual researchers with the
necessary facilities at their disposal.
In the Second International Mapping Experiment an attempt was made to combine
the advantages of individual research work with the advantages of world-wide partici-
pation. Without this approach it would have been impossible to gather such an im-
pressive amount of independent data for detailed analysis. This part of the experiment
revealed certain phenomena common to most of the submitted material. In order to
offer possible explanations for these phenomena, further investigations supported by
additional experimental flights were carried out at the National Research Council of
Canada.
Direct participation of different centers from various countries is also a stimulating
incentive for similar independent investigations. Properly organized international
studies of particularly suitable and urgent problems may greatly encourage the scientific
and technical efforts of various centers, and this may eventually lead to a more rapid
advancement in the photogrammetric field.
Finally, the international experiments organized by Commission IV of the Inter-
national Society of Photogrammetry are a splendid example of international cooperation
promoting a closer relationship between individuals from different parts of the world
and helping to establish a more personal contact among those interested in the pro-
motion of photogrammetric techniques.
PROGRAM OF THE INVESTIGATION
There is a basic difference between the Second and the First* International Mapping
Experiments. In the First Experiment only the test area was common, and the number
and quality of ground control points, aerial photographs, and the plotting equipment
used varied with each participant. It was intended to compare the various systems
used for mapping an identical area. However, wide differences in basic elements made
the comparison difficult, especially since the limited number of submissions did not
permit the elimination of the human factor from the results.
*Blachut, T. J. “Some Results from International Mapping Experiments.” Photogrammetric Engineering,
Vol. XXIII, No. 4 (September, 1957), pp. 767-774.
Bachmann, W. K. and W. Haberlin. “Rapport sur l’éssai contrôlé No. 2 ‘Vercors’. Etablissement
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photogrammétrique d'une carte à échelle 1:50,000." Report to VIIIth Congress ISP, 1956.
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