N: N un. "0 
m V rn n OO 
C 
  
Commission IV Presented paper 1 
Planning in Modern Aerial Survey 
by W. SCHERMERHORN 
LT.C., Delft. 
1. Introduction. 
In an article about *actual problems in aerial survey” published as Nr. AB1 of the 
new series of I.T.C.-publications, I tried to explain why a more general planning for an 
overall aerial survey is gradually taking place. So far it is considered entirely normal 
that aerial photographs are taken for the use of one particular service, without much 
thought of the general needs of the country. For normal ground surveys, carried out for 
some engineering project, this may be acceptable. Air photographs, however, yield mate- 
rial with such a rich quantity of information, that it would be a pity not to use them in 
the frame work of the survey of a country. 
This has only sense if there is a central authority, responsible for the economic 
planning. This service should have at least a branch with knowledge of aerial survey and 
its possibilities. We have however met several examples of insufficient planning. The 
consequence of this is that specialists of the inventory of natural resources will not have 
the necessary topographie maps available, not even on a small scale, which they must 
use as basis for their special maps. They must waste their time constructing base maps — 
which nearly always must be poor — by compiling from their air photographs, applying 
Such are examples of poor planning when the topographic service 
some primitive method. 
responsible for the economic planning of the country, with 
cannot provide the agencies, 
the necessary maps at the proper time. 
This lack of planning exists not only in so-called development countries, but also in 
highly developed and in industrialized countries. It is due to the fact one or more of the 
following conditions are not fulfilled: 
1. Planning of cartography is only possible in countries in which general economic plan- 
ning is usual. 
2. Such planning requires that the highest authorities in a country, including ministers 
and their top ranking officials, are convinced of the necessity of planning and coordi- 
nating various activities. 
3 The directors of the survey organisations must have sufficient authority and prestige 
with their collegues, in charge of agriculture, general planning etc., in order to 
guarantee serious consideration of their proposals about cartography and aerial 
survey. 
4. At the top level of the survey organisations should exist full knowledge of the latest 
aerial survey, not only in their own country but everywhere. It is 
developments in 
3rd condition. 
evident that this condition is essential for the fulfillment of the 
Looking around in the world it would be easy to find proofs in positive and in nega- 
tive sense of the truth of these conditions. I might draw attention to the fact that 
the use of camera orientation equipment, such as statoscope, solar 
periscope and horizon camera for the limitation of the propagation of errors in aerial 
is well known since 1940. Not withstanding this we see that at present large 
e, even without the use of a statoscope. This 
is in general a lack of sufficient knowledge by the authorities responsible for aerial 
Even if somebody does not need the statoscope readings for his own use e.g. in 
he should consider the use of his photo- 
the importance of 
triangulation 
photographie small-scale coverages are mad 
survey. 
case of photography for economic interpretation, 
graphic coverage for more general purposes. 
It seems that in many countries the social position of surveyors as compared with