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of our profession. As | had occasion to notice a few years ago, even some of our largest metro- 
polises were establishing their large scale maps on a shoestring, and one suspected that there were 
more careful and uniform plans of some parts of the moon than there were of these cities. 
| hope, therefore, that Commission VI will be willing to cede *he common path of compla- 
cency to other Commissions and instead take a more searching and constructive attitutde to 
overcome the embarassing state of affairs for which we cannot deny responsibility. 
Basic Components of the Present Scenario. 
For reaching changes and progress in our field were brought about by the invention and intro- 
duction of photogrammetry, or indirect surveying and mapping methads. Indirect, because the 
measuring operations take place not in the natural space, but in very precisely reconstructed mode/ 
spaces. The unique, novel and superior charcteristics of photogrammetric techniques (as compa- 
red with field or direct surveying methods) are obvious: very high speed measuring process; the 
coordinates of all numerically or graphically recorded points and line are actually precisely recon- 
structed and measured, or the interpolation widely used in the field procedures has been largely 
eliminated; very high and uniform absolute accuracy of photogrammetric determinations; general 
applicability of photogrammtric methods that can measure with equal ease inaccessible marsh 
or very steep terrain as well as flat, cultivated fields; capability of precisely measuring phenomena in 
motion such as water currents or waves; and rapid detection and recording of processes that are 
the subject of investigation by remote sensing techniques, etc. of special interest in this context 
are the relatively recently developed orthophoto and stereoorthophoto methods that combine 
singular simplicity and efficiency, with superior applicability to the surveying and mapping pro- 
jects of natural landscapes typical of developing countries. Some of these latter techniques are 
highly automated and deliver numerical and graphical data in a very rapid production process. 
Moreover, as their basic product is a very precise differentially rectified photographic image of 
the earth's surface with all the existing details complete with contour lines, their usefulness in 
mapping projects is particularly evident. 
The impressive accuracy of photogrammetric determinations (coordinates) is, however 
occasionally limited by insufficient definition in aerial photographs of the points to be measured. 
This natural limitation of photogrammetric techniques must be clearly recongnized to avoid 
grave operational mistakes, and to devise procedures to improve the results so as not to squander 
the meagre available resources on very expensive plotting equipment, which is of no use in some 
situations. For powerful modern photogrammetric equipment, particularly of the analytical 
type, there are many other demanding tasks. 
The economic rules governing photogrammetric techniques are quite different from the rules 
governing conventional field surveying operations, The cost of field work is grosso modo propor 
tional to the number of points to be measured in an area of certain characteristics. Assuming 
the availability of base survey equipment, the initial cost is insignificant. Therefore, the pro- 
cedure are well suited for small survey (or mapping) jobs. The situation in photogrammetry is 
different. The initial investment is a/ways significant and proportionally much higher in small 
projects. This is primarily due to the high cost of aerial photographs to be made and the pre- 
paratory work. There is also a difference in the cost distribution between various steps in photo- 
grammetric plotting and processing operations, with the result that the photogrammetric opera- 
tion is more economical if as many points as possible are determi ned from a single stereopair, 
or the cost of point determinationdecreases with the growing total number of points determined- 
from a stereopair. In other words: photogrammetric technique favours complete surveying and 
plotting products.