The various space programmes have forced the development of satellite and 
ballistic cameras, which show many resemblances to airborne cameras, although 
they avoid some of the environmental problems. 
The visitor to the Lausanne Congress will have the opportunity to see a 
■wide range of airborne equipment. I have only been able here to highlight 
certain areas which seem to me to be especially significant. 
(b) Films and Processing Equipment If the period I960 - 64 belonged 
to polyester film base, 19&4 - 68 belonged to colour film - both true colour 
and "false” colour. While colour film had been used as an aid to the photo- 
interpreter, it became realised that colour differentiation itself could help 
the operator of the plotting machine. As a result, colour emulsions have been 
coated onto polyester base to ensure geometric qualities. All the major film 
manufacturers have such films available and the literature abounds in papers 
giving the results of measurements in the laboratory and in the field. The 
conclusions are clear; colour film i. e. natural colour film, retains all the 
geometric and resolution qualities of black and white film, while giving con 
siderable interpretation advantages. The only advantages left for black and 
white are cost and to some extent film speed. There is not yet the colour 
equivalent to the high speed, albeit grainy, films commonly used in some low 
altitude applications. Finland and Sweden have both stressed the need for such 
films, so that this may be even more important in high latitudes. 
Automatic film processing and printing machines make steady progress and 
have been adapted for use with colour film. An interesting development is 
reported from Czechoslovakia where an electronic printer is used not only for 
exposure equalisation but also for colour correction. This machine can take 
out the blue "haze" experienced in high altitude photography, and so restore 
the colour balance in prints or diapositives, 
British workers have already reported that colour films show maximum 
advantage under conditions of poor visibility. Colour correction should make 
matters even better. 
The remaining controversy is on the use of "false" colour or "natural" 
colour. Once the photographer is released from the shackles of black and white 
it is but a short step to question whether Nature has provided optimum colour - 
or whether Nature can be improved upon. Many countries are working upon this 
problem end I expect to hear a lot about it at this Congress. 
(c) Navigation In military and civil aviation, there has been immense 
progress in navigation equipment during; the lest five years Very little of 
this progress has been reflected in aircraft for survey purposes While experi 
ments with inertial platforms and radio aids have been reported in the literature, 
air surveys are still carried out with primative navigation equipment, This 
situation will continue to exist until our navigation specialists make the effort 
to examine the special problem of air survey, and come up with a system whose 
economic advantages can be demonstrated. I stress the word "system"; it is most 
unlikely in my view that the mere addition of a "navigator" will prove satisfactory. 
Only when the data available in a navigation system is used to control the aircraft, 
expose the cameras, and add the ground plotting, will the capital cost prove 
worthwhile. 
(d) Performance Evaluation At Lisbon, the use of the "optical transfer 
function" (O.T.F.) was limited "to a few research applications. The subject is 
now much better understood, and OTF measurements are now everyday affairs. Indeed 
/it is