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Although it might contain to à certain extent more information than a line 
map, this information can hardly be extracted by an average map user, 
On the other hand, photomaps as preliminary maps in the context of the 
proposed system certainly serve many urgent requirements, and in any case 
they are far better than no maps at all. 
Furthermore, it can be stated that for certain purposes, such as their use 
as base maps for resources surveys, photomaps are even preferable to line 
maps, as they allow an easier and faster transfer of ihe interpretation 
result from the aerial photography to the base map. 
b) The execution of phase A 
  
Especially with respect to smaller countries, with limited financia 
resources for mapping purposes, it might be preferable to have the first 
phase executed by either a specialized contractor or by regional production 
centres, serving a number of countries and thereby facilitating the necessary 
investment in equipment, human resources and skill. 
If not otherwise possible, it might also be feasible to have this phase of 
the work, or at least certain parts of it, executed by special technical 
units to be attached to UN organisations like FAO, T.A., etc. 
c) The role of technical assistance 
  
This first phase of the total project might also be subject to technical 
assistance, rendered to development countries on a bilateral or multilateral 
basis. It obviously fulfils to a large extent the basic principle of technical 
aid, namely to initiate with relatively small funds an as large as possible 
national contribution of the receiving country. 
At the same time, this type of technical assistance also facilitates a lot of 
; 2 lj rati Y i 
other development activities (national resources survey, integrated surveys, 
etc.). 
Interrelation of topographic mapping programme with resources surveys 
  
If in the context of a development programme for a certain area, individual 
resources surveys (soils, forestry, hydrology, etc.) or an integrated survey has 
to be carried out, the conventional mapping systems are too slow and too expen- 
sive to provide the required topographic base maps - if they do not already 
exist. 
As à consequence, the resources surveyors have to provide their own base maps 
(uncontrolled mosaics, slotted templet layouts, etc.) to present the data 
gathered in the form of maps.