57 
that this gathering of data represents probably about 90% of the 
effort and cost of a land information system. This shows the 
result of letting computer experts and geographers get the upper 
hand in this field. Unfortunately they do not understand the 
basic requirements of surveying and mapping. They are assuming 
that the "data" is somehow available. They are also not aware 
of the fundamental principle ruling surveying and mapping 
operations which states that "smaller scale" products can be 
derived from the " larcrer scale“ data but not vice versa. 
Therefore, since one can not avoid relatively precise and 
detailed measuring operations in the field or by using 
photogrammetry, the proper and only economic solution in the age 
of computers is to carry out tnese measurements correctly, and 
then derive smaller seale and generalized products from them by 
the use of computers. Ev doing so, the precise up-to-date 
terrain data would be available whenever required. Delays, 
duplications and blunders would be eliminated and the savings 
'would be enormous. Moreover, a needed base would be created for 
the acquisition and efficient use of other data such a.s that 
provided by remote sensing techniques. 
To keep the various surveying and mapping techniques in a 
natural operational structure, it is not sufficient to rename 
societies and their journals. One must formulate new operational 
principles and rational specifications including alternative 
measures that permit the use of photogrammetry. After all, it 
is the only technique capable of solving without delay the 
pressing problems in the field under discussion. The guiding 
factors must be the actual requirements of society at larcre and 
not the vanity or commercial interests of various groups. 
Photogrammetry, because of its wide range of applications and 
singular efficiency, forms an obvious base for such a 
comprehensive and integrated land information system. Such a 
system is urgently needed in all countries, but in particular in 
developing countries. They do not have the time or resources to 
enjoy the "luxury" of obsolete schemes. 
In order to achieve this goal some organized effort on our 
side is required. First of all, we should ask ourselves the 
basic question: Are we satisfied with the present state of 
surveying and mapping in the world, and do we really think we 
have carried out cur responsibility in this field? If the answer 
in "No", we should then ask ourselves, "How did this happen?". 
We know mat pcwerrul and economic facilities are provided by 
photogrammetry; why the lack of progress? 
Secondly, if we. are concerned enough not to be satisfied 
with the present situation, we should remind national and 
international institutions that as far back as 1972 the UN 
Secretary General appointed an Ad Hoc Group of Experts * that 
subsequently issued a report entitled ,, Medium-Scaie”and Large- 
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