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obtained from a large. block triangulation carried out under ordinary operational 
conditions. The results are indeed instructive. It may be of interest to 
remark here that, when the efficiency of photogrammetric operations is considered, 
the speed and costs are seldom discussed as factors of equal importance. One 
would like to hope that in view of the urgent needs in the mapping field, the 
rate of production will be given much greater consideration than it has received 
in the past. In many instances, time is a much more important factor than cost. 
Of course, the best solution is a combination of production speed and low costs 
-- this is the case with analytical aerial triangulation for mapping purposes. 
Analytical aerial triangulation over large areas (or, more generally, of large 
blocks of photographs) eliminated the difficulty that often was referred to as 
a "bottleneck" in mapping operations. When supported by such airborne methods 
as the fadar Profile and Aerodist, this method permits to determine rapidly the 
necessary control points under the most difficult circumstances. Please refer 
to Specialized publications in this regard 2,3,4 . I would like, however, to 
mention en passant, that the laser type of profile Recorder is in sn advanced 
experimental stage 5 . There is no doubt that this new technique, which 
promises astonishing performance, will further equip photogrammetry with a 
powerful tool for the task of mapping large and remote territories. 
Orthophoto maps 
The intent to develop an automatic mapping technique, pursued from 
the earliest days of photogrammetry, found its fulfillment in the orthophoto 
technique. This is probably one of the most remarkable events in mapping 
history. Yet, it is seldom recognized as such partly because of the novelty of 
the product. The orthophoto map is vastly different from the conventional map: 
the latter is a symbolized picture of an abstract of the earth's surface, whereas 
the former is its geometrically correct, true photographic picture. The content 
of the conventional map is decided upon at the design stage, whereas the ortho- 
photo map, in principle, includes all the cartographic information of the terrain, 
and it is up to the user to interpret and to select information according to his 
need, 
  
Some mappers and cartographers have the tendency to reject spontaneously 
the orthophoto product as a new concept in mapping because the orthophoto map 
does not meet the classic definition of a map. Conversely, it could be reasoned, 
that only because an orthophoto is sufficiently different from the conventional 
map is there a chance of a far-reaching solution, presenting exceptional advan- 
tages and possibilities from the standpoint of production. 
Leaving this question aside, let us analyze the new vistas open to 
mapping and to small-scale mapping by the orthophoto approach. There are some 
important features of this technique that must be considered from the outset to 
make the discussion meaningful: 
-Contouring and relief shading is obtained automatically and simultaneously 
with the orthophoto process. The resulting time and cost savings are of 
the utmost importance, not only in the ordinary sense, but also because 
they &llow new approaches to mapping projects of particular urgency or of 
a temporary nature, 
-Orthophoto technique offers a new approach to mapping in general, including 
conventional mapping, where a linedrawn map is the final product, The 
development of the stereo orthophoto should be mentioned particularly in 
this connection. 
As I tried to explain on previous occasions, there is an obvious rela- 
tionship between the tool and product: they should be permitted to act on each 
other until an optimum solution is achieved. Any rigid, preconceived ideas or 
specifications introduce undue difficulties and slow the progress. It is impor- 
tant, when considering the orthophoto technique as a new mapping tool, that we