4. PROCEDURES 5. APP 
No really significant changes have been reported in this section of the question e a) 
/ ^ 
naire dealing with the phases of the execution of a project and the introduction 
of special procedures. 
a) Colour photography The answers from the reporting countries on this topic 
Seem to be somewhat contrary to the statements issued during the Delft 
symposium. At that time the impression was given that colour photography was 
being used extensively in a number of countries, which is, however, not borne 
out in the reports. 
Its major application is without doubt still in the field of photo interpret- 
ation. Colour photography has also been used for experiments in coastal 
surveys and in a number of projects, at the client's request. One Australian 
firm states that it uses colour and has found that the plotting rate has bye: 
increased, misidentification is less, the accuracy is greater and that there 
is better shadow interpretation. 
b) Use of more than one photoscale in a single project 
The reports on this item vary from more than one photoscale being rarely used 
to its use being common practice. @ e 
The most common application, reported by France, Hungary, South Africa and the 
U.K., is to use the smaller scale photography in aerial triangulation and the 
larger scale in plotiing. 
Mexico and the U.K. report the use of the smaller scale photography in mapping 
and the larger scale (in Mexico's case, colour photography) to aid in inter- 
pretation and identification. The photography is in most cases obtained in 
Separate flights. 
c) Photo interpretation In general, no changes have been reported. Australia 
  
and Sweden are making limited use of remote sensing imagery for interpretation 
purposes, whereas the U.S.S.R. report that they are able to effectively carry 
out field verification from helicopters. 
d) Field completion Again, most countries report that there have been no changes. 
Australia's report, one of the most complete, shows that approximately 80% 
of their general purpose work is checked against 50% of the special purpose e € 
work. Checks of individual phases and the final product are always performed 
by the mapping authority and occasionally by independent agencies. The checks 
of the final product tend to lay more emphasis on completeness rather than 
on accuracy.